Cluster operator image-registry is not available during OpenShift 4.12 upgrade on AWS

Issue

• Image Registry Operator is in degraded status with the following error.

$ oc get co | grep -i image-registry
image-registry                                       False       True          True       2h

• Further checking the condition status of image-registry cluster operator.

$ oc get co image-registry -o json |jq -r '.status.conditions[]'
"lastTransitionTime": "2023-09-25T18:32:37Z",
"message": "Degraded: The deployment does not have available replicas",
"reason": "Unavailable",
"status": "True",
"type": "Degraded"

• Looking at the clusterversion status message.

$ oc get clusterversion
NAME      VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
version             False       True          1h46m   Unable to apply 4.12.34: the cluster operator image-registry is not available