Remove the mr_push_options feature flag

`Gitlab::QueryLimiting.whitelist` has been moved from being inside the
feature flag conditional check to the `process_mr_push_options`
`Api::Internal` helper.

https://gitlab.com/gitlab-org/gitlab-ce/issues/60250

lib/api/helpers/internal_helpers.rb

@@ -46,6 +46,8 @@ module API
       def process_mr_push_options(push_options, project, user, changes)
         output = {}
 
+        Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-ce/issues/61359')
+
         service = ::MergeRequests::PushOptionsHandlerService.new(
           project,
           user,

lib/api/internal.rb

@@ -264,12 +264,8 @@ module API
         PostReceive.perform_async(params[:gl_repository], params[:identifier],
           params[:changes], push_options.as_json)
 
-        if Feature.enabled?(:mr_push_options, default_enabled: true)
-          Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-ce/issues/61359')
-
         mr_options = push_options.get(:merge_request)
         output.merge!(process_mr_push_options(mr_options, project, user, params[:changes])) if mr_options.present?
-        end
 
         broadcast_message = BroadcastMessage.current&.last&.message
         reference_counter_decreased = Gitlab::ReferenceCounter.new(params[:gl_repository]).decrease

spec/requests/api/internal_spec.rb

@@ -997,18 +997,6 @@ describe API::Internal do
 
         expect(json_response['warnings']).to eq('Error encountered with push options \'merge_request.create\': my error')
       end
-
-      context 'when the feature is disabled' do
-        it 'does not invoke MergeRequests::PushOptionsHandlerService' do
-          stub_feature_flags(mr_push_options: false)
-
-          expect(MergeRequests::PushOptionsHandlerService).not_to receive(:new)
-
-          expect do
-            post api('/internal/post_receive'), params: valid_params
-          end.not_to change { MergeRequest.count }
-        end
-      end
     end
 
     context 'broadcast message exists' do