Unable to upgrade an RHOCP cluster due to warning on console: Highly-available workload single point of failure.

Issue

• When upgrading to an RHOCP cluster, a warning pops up on the console:

The highly-available workload in namespace openshift-monitoring, with label map["app.kubernetes.io/name":"prometheus"] and persistent storage, enabled, has a single point of failure.
      Manual intervention is needed to upgrade to the next minor version. For each highly-available workload that has a single point of failure please mark at least one of their PersistentVolumeClaim for deletion by annotating them with a map["openshift.io/cluster-monitoring-drop-pvc":"yes"].

• The cluster is not able to upgrade to the next minor version.

• Manual intervention is needed to upgrade to the next minor version.