nixos/rancher: fix multi node test (#505225)

      # Now create a pod on each node via a daemonset and verify they can talk to each other.

      server.succeed("kubectl apply -f ${networkTestDaemonset}")

      server.wait_until_succeeds(f'[ "$(kubectl get ds test -o json | jq .status.numberReady)" -eq {len(machines)} ]')

      server.wait_until_succeeds("kubectl rollout status daemonset test")

      # Get pod IPs

      pods = server.succeed("kubectl get po -o json | jq '.items[].metadata.name' -r").splitlines()