salt: Deploy certificates beacon on nodes with role node

Since this is needed on almost any node, let's
deploy the beacons on all nodes, if there is
no certificate to watch it will do nothing anyway.

Refs: #1887

salt/metalk8s/roles/node/init.sls

@@ -4,3 +4,4 @@ include:
   - metalk8s.kubernetes.kubelet
   - metalk8s.kubernetes.apiserver-proxy
   - metalk8s.internal.preflight
+  - metalk8s.beacon.certificates