Set `remove_source_branch: true` when creating a merge request
I think this makes the most sense for the prep MRs, which are ephemeral and should be removed after merging by default.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
I think this makes the most sense for the prep MRs, which are ephemeral and should be removed after merging by default.