Fix merge request API after #7526
Created by: Razer6
#7526 changed the way how labels get validated. Since merge requests allows adding labels the same like issues, this needs also to be fixed here.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Created by: Razer6
#7526 changed the way how labels get validated. Since merge requests allows adding labels the same like issues, this needs also to be fixed here.