Enable and remove the FF ci_rule_exists_extension_optimization

It's already enabled on GitLab.com since 2024-03-05.

Changelog: performance

config/feature_flags/gitlab_com_derisk/ci_rule_exists_extension_optimization.yml

----
-name: ci_rule_exists_extension_optimization
-feature_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/227632
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143056
-rollout_issue_url: https://gitlab.com/gitlab-com/gl-infra/production/-/issues/17531
-milestone: '16.9'
-group: group::pipeline authoring
-type: gitlab_com_derisk
-default_enabled: false

lib/gitlab/ci/build/rules/rule/clause/exists.rb

@@ -16,10 +16,6 @@ def initialize(globs)
         end
 
         def satisfied_by?(_pipeline, context)
-          if ::Feature.disabled?(:ci_rule_exists_extension_optimization, context.project, type: :gitlab_com_derisk)
-            return legacy_satisfied_by?(context)
-          end
-
           paths = worktree_paths(context)
           exact_globs, extension_globs, pattern_globs = separate_globs(context)
 
@@ -30,18 +26,6 @@ def satisfied_by?(_pipeline, context)
 
         private
 
-        def legacy_satisfied_by?(context)
-          paths = worktree_paths(context)
-          exact_globs, pattern_globs = legacy_separate_globs(context)
-
-          exact_matches?(paths, exact_globs) || pattern_matches?(paths, pattern_globs)
-        end
-
-        def legacy_separate_globs(context)
-          expanded_globs = expand_globs(context)
-          expanded_globs.partition(&method(:exact_glob?))
-        end
-
         def separate_globs(context)
           expanded_globs = expand_globs(context)
 

spec/lib/gitlab/ci/build/rules/rule/clause/exists_spec.rb

@@ -11,16 +11,6 @@
         let(:project) { create(:project, :custom_repo, files: files) }
       end
 
-      context 'with feature flag `ci_rule_exists_extension_optimization` disabled' do
-        before do
-          stub_feature_flags(ci_rule_exists_extension_optimization: false)
-        end
-
-        it_behaves_like 'a glob matching rule' do
-          let(:project) { create(:project, :custom_repo, files: files) }
-        end
-      end
-
       context 'when the rules:exists has a variable' do
         let_it_be(:project) { create(:project, :custom_repo, files: { 'helm/helm_file.txt' => '' }) }