cephrgw: allow purge-on-delete for cnpg backup buckets (#313)

Step 1 of moving the CNPG backup buckets to ec placement: RGW can't move an existing bucket, so they must be dropped and recreated. This lets the operator actually delete the buckets (with their objects) when the CRs are removed in step 2.

- set retainOnDelete: false and purgeOnDelete: true on all nine cnpg backup Bucket CRs
- leave ObjectStoreUser/BucketAccess untouched so the backup-s3 secrets persist

Reviewed-on: #313
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

apps/base/netbox/cnpg_backup.yaml

@@ -32,7 +32,8 @@ spec:
   tags:
     app: netbox
     purpose: cnpg-backup
-  retainOnDelete: true
+  retainOnDelete: false
+  purgeOnDelete: true
 ---
 apiVersion: postgresql.cnpg.io/v1
 kind: ScheduledBackup