Enable frozen string for lib/gitlab/ci

Enables frozen string for the following:

* lib/gitlab/ci/*.rb
* lib/gitlab/ci/build/**/*.rb
* lib/gitlab/ci/config/**/*.rb
* lib/gitlab/ci/pipeline/**/*.rb
* lib/gitlab/ci/reports/**/*.rb

Partially addresses #47424.

changelogs/unreleased/frozen-string-enable-lib-gitlab-ci.yml

+---
+title: Enable frozen string for lib/gitlab/ci
+merge_request:
+author: gfyoung
+type: performance

lib/gitlab/ci/ansi2html.rb

+# frozen_string_literal: true
+
 # ANSI color library
 #
 # Implementation per http://en.wikipedia.org/wiki/ANSI_escape_code
@@ -265,7 +267,7 @@ module Gitlab
         def reset_state
           @offset = 0
           @n_open_tags = 0
-          @out = ''
+          @out = +''
           reset
         end
 

lib/gitlab/ci/build/artifacts/adapters/gzip_stream.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/artifacts/adapters/raw_stream.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/artifacts/metadata.rb

+# frozen_string_literal: true
+
 require 'zlib'
 require 'json'
 

lib/gitlab/ci/build/artifacts/metadata/entry.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/artifacts/path.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/credentials/base.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/credentials/factory.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/credentials/registry.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/image.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/policy.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/policy/kubernetes.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/policy/refs.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/policy/specification.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/policy/variables.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/build/step.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Build

lib/gitlab/ci/charts.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Charts

lib/gitlab/ci/config.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     #

lib/gitlab/ci/config/entry/artifacts.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/attributable.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/boolean.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/cache.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/commands.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/configurable.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/coverage.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/environment.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/factory.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/global.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/hidden.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/image.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/job.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/jobs.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/key.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/legacy_validation_helpers.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/node.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/paths.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/policy.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/script.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/service.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/services.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/simplifiable.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/stage.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/stages.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/undefined.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/unspecified.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/validatable.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/validator.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/validators.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/entry/variables.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/config/loader.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Config

lib/gitlab/ci/cron_parser.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class CronParser

lib/gitlab/ci/mask_secret.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci::MaskSecret
     class << self
       def mask!(value, token)
         return value unless value.present? && token.present?
 
+        # We assume 'value' must be mutable, given
+        # that frozen string is enabled.
         value.gsub!(token, 'x' * token.length)
         value
       end

lib/gitlab/ci/model.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Model

lib/gitlab/ci/pipeline/chain/base.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/build.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/command.rb

-module Gitlab # rubocop:disable Naming/FileName
+# rubocop:disable Naming/FileName
+# frozen_string_literal: true
+
+module Gitlab
   module Ci
     module Pipeline
       module Chain

lib/gitlab/ci/pipeline/chain/create.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/helpers.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/populate.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/sequence.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/skip.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/validate/abilities.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/validate/config.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/chain/validate/repository.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/duration.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/base.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/equals.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/matches.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/null.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/operator.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/pattern.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/string.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/value.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexeme/variable.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/lexer.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/parser.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/statement.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/expression/token.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/seed/base.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/seed/build.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/pipeline/seed/stage.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Pipeline

lib/gitlab/ci/reports/test_case.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Reports

lib/gitlab/ci/reports/test_reports.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Reports

lib/gitlab/ci/reports/test_reports_comparer.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Reports

lib/gitlab/ci/reports/test_suite.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Reports

lib/gitlab/ci/reports/test_suite_comparer.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     module Reports

lib/gitlab/ci/trace.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class Trace

lib/gitlab/ci/yaml_processor.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Ci
     class YamlProcessor