Fixing two migrations that could not be rolled back
Found these while trying to rollback 9-0-stable to 8.17.3
Related to the RC1 release testing: https://gitlab.com/gitlab-org/gitlab-ce/issues/29170
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Found these while trying to rollback 9-0-stable to 8.17.3
Related to the RC1 release testing: https://gitlab.com/gitlab-org/gitlab-ce/issues/29170