The check for a Backup an earlier reconcile already created returned
its read error, and the drivers turn any error from that path into a
terminally Failed BackupJob. An apiserver timeout right after the
operator backup completed therefore lost a backup whose data was safely
in S3. The check only saves a probe, and the Create that follows already
handles an existing Backup, so log the error and go on to Create.
A trailing slash on the S3 endpoint is not a path prefix; the operators
accept it, so do not refuse it.
Pin the uncached AlreadyExists refetch, the upper slack of the MariaDB
window and the probe timeout with tests.
Assisted-by: LLM
Signed-off-by: Andrey Kolkov <androndo@gmail.com>