Zero the min-ready for arm64 node labels
Zero the min-ready for arm64 node labels

We presently have a very limited quota for arm64 nodes, so
particularly ones like the xxlarge type can occupy a significant
percentage for hours with just a single min-ready node waiting for a
build to request it. For now, keep no ready arm64 nodes and let them
be booted on demand instead. This does mean builds will spend longer
waiting on some node requests, but should also increase our overall
throughput at peak load by maximizing the available quota for
actually requested nodes.

Change-Id: I3ab12c8186fe66f9f539941eb2fbec40d22b4354

openstack-infra/project-config,openstack-infra/project-config