Cannot evict rook-ceph-mon pod due to pod violating PodDisruptionBudget in OCS 4.x

Issue

• OCP upgrade stuck on OCS node and machine-config-daemon reporting cannot evict mon pod.

  # oc logs machine-config-daemon-12345 -f -c machine-config-daemon
  I0721 21:02:27.039558 1483239 update.go:92] error when evicting pod "rook-ceph-mon-a-aaaabbbb-cccc" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget.
  

• While draining OCS node theoc adm drain command waiting for mon pod to get evicted

  # oc adm drain rhocs02 --ignore-daemonsets=true --delete-local-data=true --force
  error when evicting pod "rook-ceph-mon-a-ccccdddd-aaaa" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget.