KPET-DB: Pick up new composes automatically
We regularly face the problem of distro composes being removed from Beaker. Most recent one was with RHEL-8.2. It turns out those particular ones are removed only after two weeks of being there.
Consider implementing automatic switch-over to new composes. We can have a script discover new composes automatically every few days, create an MR for kpet-db updating it, and trigger a pipeline run with it. Then a human can come over check it out and possibly merge it. The script can decide which composes are new and which are old by finding the latest one among what's in kpet-db and what's in the MRs it created. Anything newer than that would be a candidate for a new MR.
JIRA ticket created by @nkondras