Include release label

See https://issues.redhat.com/browse/RHEL-102465 and https://gitlab.com/redhat/rhel/bifrost/rhel-bootc/-/merge_requests/3172

I was going to sync this to the current centos pipeline(s) then realized it made sense to try changing this one first.

I'm filing this instead of working on the code because #1 has me confused as to the state/goal of this repo.