Add patch verb to deployment resource

Dashboard fails with ```failed restoring revision 21: deployments.apps "ourapp" is forbidden: User "system:serviceaccount:argo-rollouts:argo-rollouts-dashboard" cannot patch resource "deployments" in API group "apps" in the namespace "ournamespace"``` when trying to rollback `Rollout` defined using existing `Deployment` and `workloadRef` config.
Adding `patch` verb for `deployments` should fix it.

manifests/dashboard-install/dashboard-clusterrole.yaml

@@ -49,6 +49,7 @@ rules:
       - update
       - list
       - watch
+      - patch
   - apiGroups:
       - apps
     resources: