Only send one notification for failed remote mirror (EE port)
Retries in Sidekiq and in the remote mirror scheduler can cause repeated attempts in quick succession if the sync fails. Each failure will then send an e-mail to all project maintainers, which can spam users unnecessarily.
Modify the logic to send one notification the first time the mirror
fails by setting error_notification_sent
to true
and reset the
flag after a successful sync.
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56222
CE port: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/24381