From https://bugzilla.mozilla.org/show_bug.cgi?id=487235#c2 production-prometheus-vm we will have to keep too, we use it to for tag, source, updates, update verify, and stage. We could possibly consolidate nightly updates from proemtheus-vm onto this box, so remove one more VM. This will allow us to mothball prometheus-vm.
We're moving update generation to the slaves, and the other steps are already done by the pool of slaves.
Moving closed Future bugs into Release Engineering in preparation for removing the Future component.