pg backups filled up

we're having a disk full issue on backup-storage-01, investigate.

possibly related to recent changes made in the pgbackrest puppet module, which might have also caused the latency issue (#41980 (closed)).

oddly similar to the backup issues we've had on the other server (#41372 (closed)), see how our disk usage compares.

here's the grafana dashboard since we started:

https://grafana.torproject.org/d/zbCoGRjnz/disk-usage?from=now-45d&to=now&var-instance=backup-storage-01.torproject.org&var-Filters=mountpoint|=|/srv/backups/pg&timezone=utc&orgId=1&var-class=$__all&refresh=auto&viewPanel=panel-4-clone-0