Remove `verify_protected_tags_for_pull_mirror` feature flag

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/352494

Changelog: other

config/feature_flags/development/verify_protected_tags_for_pull_mirror.yml

----
-name: verify_protected_tags_for_pull_mirror
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/80388
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/352494
-milestone: '14.9'
-type: development
-group: group::source code
-default_enabled: true

ee/app/services/projects/update_mirror_service.rb

@@ -114,7 +114,7 @@ module Projects
 
         next if old_tag_target == tag_target
 
-        if Feature.enabled?(:verify_protected_tags_for_pull_mirror, project, default_enabled: :yaml) && !can_create_tag?(tag)
+        unless can_create_tag?(tag)
           tags_to_remove << tag
           next
         end

ee/spec/services/projects/update_mirror_service_spec.rb

@@ -159,23 +159,6 @@ RSpec.describe Projects::UpdateMirrorService do
             expect(project.repository.tag_names).not_to include('protected-tag')
             expect(project.repository.tag_names).to include('new-tag')
           end
-
-          context 'when feature flag is disabled' do
-            before do
-              stub_feature_flags(verify_protected_tags_for_pull_mirror: false)
-            end
-
-            it 'creates the protected tag' do
-              stub_fetch_mirror(project)
-
-              expect(project.repository).to receive(:expire_tags_cache).and_call_original
-              expect(Git::TagPushService).to receive(:new).and_call_original.twice
-
-              expect(service.execute).to eq(status: :success)
-
-              expect(project.repository.tag_names).to include('new-tag', 'protected-tag')
-            end
-          end
         end
       end
     end