Please remove the DNS entry for op-ab.onionperf.torproject.net
#34018 (moved) removes this from CollecTor configuration, and the host is currently being shut down as I write this ticket.
I don't know if there's any question as to what to do about TLS certs issued to domain names. In an ideal world we'd track these and not reuse names until we're sure the certs would be expired. There is a Lets Encrypt cert issued to this name that will also be in backups, destroying it would be difficult, but I can revoke the certs:
I've done this for the two non-expired certs.