As https://main-jenkins-csb-crwqe.apps.ocp-c1.prod.psi.redhat.com/computer/crwjen-1.s390/ was dropped because it was broken, and https://main-jenkins-csb-crwqe.apps.ocp-c1.prod.psi.redhat.com/computer/crwjen-3.s390/ continues to be offline/unreachable, we cannot use s390x as a label for generic jobs, as that would prevent chained jobs from ever running (if crwjen-2.s390 is running and triggers a subtask on s390x, it will never complete).

So we should remove all label refs that have x||z||p, and switch to only x||p.

We could also consider allowing crwjen-2.s390 to run multiple builds in parallel.