DBaaS: DB clusters of force unregistered k8s cluster stay listed

User imapct:

User is stuck with DB clusters in UI which should not be listed

STR:

Go to DBaaS and register one k8s cluster
Create a DB cluster
Force unregister the k8s cluster
Go back to DB Cluster tab

Expected result:

DB cluster of unregistered k8s clusters should not be listed

Actual result:

Peek 2022-08-10 17-41.webm

^{localhost.har}