You have deleted a PVC. However, either the PVC or PV deletion is stuck in the terminating state, similar to the following:

$ kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-bbf2b01e-2a69-4c4c-b9c2-48921959c363 20Gi RWO Delete Terminating default/mysql-pv-claim gp2 7m45s

Edit the stuck PVs or PVCs in the terminating state:

$ kubectl edit pv <PV_Name>

Remove finalizers similar to - kubernetes.io/pv-protection, and save the changes.