Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Related to https://gitlab.com/gitlab-com/www-gitlab-com/-/issues/10557#note_524309799 and https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5429.
Blocking https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/5080 and https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56110.