[bitnami/metallb] Add missing rule to controller role (#16992)

The clusterrole in the bitnami chart does not match some of the rbac
rules from the upstream sources. This change adds a missing rule for
listing nodes in the cluster as per the
[upstream](e708fc9010/config/rbac/role.yaml (L17-L22))
configuration

Signed-off-by: Paul Nicholson <brenix@gmail.com>

bitnami/metallb/templates/controller/rbac.yaml

@@ -23,6 +23,12 @@ rules:
       - list
       - watch
       - update
+  - apiGroups:
+      - ''
+    resources:
+      - nodes
+    verbs:
+      - list
   - apiGroups:
       - ''
     resources: