Resolves op17-2 #1
Ray reads an unspecified node count as every node alive in the cluster, and the
kubernetes backend turned that same None into one Job completion. A caller that
asked for a multi-node conversion without naming a count therefore ran it on a
single node, which is exactly the case a conversion needing several nodes' gpu
memory cannot survive. A deployment has no alive-node set to stand in for the
missing count, so refuse it, and let the GLM-4.5 launcher pass the node count it
was configured with.