Remove `:ci_release_generation` feature flag

Removes `:ci_release_generation` and related tests.

app/models/ci/build.rb

@@ -857,8 +857,7 @@ module Ci
     end
 
     def multi_build_steps?
-      options.dig(:release)&.any? &&
-        Gitlab::Ci::Features.release_generation_enabled?
+      options.dig(:release)&.any?
     end
 
     def hide_secrets(trace)

lib/gitlab/ci/build/step.rb

@@ -21,8 +21,6 @@ module Gitlab
           end
 
           def from_release(job)
-            return unless Gitlab::Ci::Features.release_generation_enabled?
-
             release = job.options[:release]
             return unless release
 

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

@@ -22,12 +22,6 @@ module Gitlab
             validates :config, allowed_keys: ALLOWED_KEYS + PROCESSABLE_ALLOWED_KEYS
             validates :config, required_keys: REQUIRED_BY_NEEDS, if: :has_needs?
             validates :script, presence: true
-            validates :config,
-              disallowed_keys: {
-                in: %i[release],
-                message: 'release features are not enabled'
-              },
-              unless: -> { Gitlab::Ci::Features.release_generation_enabled? }
 
             with_options allow_nil: true do
               validates :allow_failure, boolean: true

lib/gitlab/ci/features.rb

@@ -34,10 +34,6 @@ module Gitlab
         Feature.enabled?(:ci_pipeline_status_omit_commit_sha_in_cache_key, project, default_enabled: true)
       end
 
-      def self.release_generation_enabled?
-        ::Feature.enabled?(:ci_release_generation, default_enabled: true)
-      end
-
       # Remove in https://gitlab.com/gitlab-org/gitlab/-/issues/224199
       def self.store_pipeline_messages?(project)
         ::Feature.enabled?(:ci_store_pipeline_messages, project, default_enabled: true)

lib/gitlab/ci/yaml_processor.rb

@@ -115,7 +115,7 @@ module Gitlab
       end
 
       def release(job)
-        job[:release] if Gitlab::Ci::Features.release_generation_enabled?
+        job[:release]
       end
 
       def stage_builds_attributes(stage)

spec/lib/gitlab/ci/yaml_processor_spec.rb

@@ -1641,29 +1641,12 @@ module Gitlab
           }
         end
 
-        context 'with feature flag active' do
-          before do
-            stub_feature_flags(ci_release_generation: true)
-          end
-
         it "returns release info" do
           expect(processor.stage_builds_attributes('release').first[:options])
             .to eq(config[:release].except(:stage, :only))
         end
       end
 
-        context 'with feature flag inactive' do
-          before do
-            stub_feature_flags(ci_release_generation: false)
-          end
-
-          it 'raises error' do
-            expect { processor }.to raise_error(
-              'jobs:release config release features are not enabled: release')
-          end
-        end
-      end
-
       describe '#environment' do
         let(:config) do
           {

spec/services/ci/create_pipeline_service_spec.rb

@@ -982,7 +982,6 @@ RSpec.describe Ci::CreatePipelineService do
     context 'with release' do
       shared_examples_for 'a successful release pipeline' do
         before do
-          stub_feature_flags(ci_release_generation: true)
           stub_ci_pipeline_yaml_file(YAML.dump(config))
         end