Merge branch 'fix-loading-metrics-gems' into 'master'

Remove metrics group in Gemfile

See merge request gitlab-org/gitlab!65157

Gemfile

@@ -335,13 +335,9 @@ gem 'peek', '~> 1.1'
 gem 'snowplow-tracker', '~> 0.6.1'
 
 # Metrics
-group :metrics do
-  gem 'method_source', '~> 1.0', require: false
-  gem 'webrick', '~> 1.6.1', require: false
-
-  # Prometheus
-  gem 'prometheus-client-mmap', '~> 0.12.0'
-end
+gem 'method_source', '~> 1.0', require: false
+gem 'webrick', '~> 1.6.1', require: false
+gem 'prometheus-client-mmap', '~> 0.12.0', require: 'prometheus/client'
 
 group :development do
   gem 'lefthook', '~> 0.7.0', require: false

config/initializers/7_prometheus_metrics.rb

 # frozen_string_literal: true
 
-require 'prometheus/client'
-
 # Keep separate directories for separate processes
 def prometheus_default_multiproc_dir
   return unless Rails.env.development? || Rails.env.test?

lib/gitlab/metrics/exporter/base_exporter.rb

 # frozen_string_literal: true
 
+require 'webrick'
+require 'prometheus/client/rack/exporter'
+
 module Gitlab
   module Metrics
     module Exporter

lib/gitlab/metrics/exporter/sidekiq_exporter.rb

 # frozen_string_literal: true
 
-require 'webrick'
-require 'prometheus/client/rack/exporter'
-
 module Gitlab
   module Metrics
     module Exporter

lib/gitlab/metrics/exporter/web_exporter.rb

 # frozen_string_literal: true
 
-require 'webrick'
-require 'prometheus/client/rack/exporter'
-
 module Gitlab
   module Metrics
     module Exporter

lib/gitlab/metrics/prometheus.rb

 # frozen_string_literal: true
 
-require 'prometheus/client'
-
 module Gitlab
   module Metrics
     module Prometheus