fix(kafka): remove ZooKeeper PVCs on uninstall (#2679)

## What this PR does

Aligns ZooKeeper storage cleanup with the existing Kafka broker behavior
so deleting a Kafka release reclaims all of its persistent storage. The
Strimzi `Kafka` CR template already set `deleteClaim: true` on the
broker JBOD volume, but the ZooKeeper persistent-claim was left at
`deleteClaim: false`. As a result, removing a Kafka application freed
the broker PVCs while orphaning the ZooKeeper PVCs in the tenant
namespace, requiring manual cleanup before the same release name could
be reused.

The change is a single field flip in
`packages/apps/kafka/templates/kafka.yaml` on the
`spec.zookeeper.storage` block.

### Behavior change

Users who previously relied on orphaned ZooKeeper PVCs as an implicit
"soft delete" for ZooKeeper state recovery should be aware that
uninstalling a Kafka release now also removes the underlying ZooKeeper
storage. Take a backup before deletion if ZooKeeper data retention is
required.

### Screenshots

Not applicable — no UI changes.

### Release note

```release-note
fix(kafka): ZooKeeper PVCs are now reclaimed when a Kafka release is deleted, matching the existing Kafka broker storage behavior.
```


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Chores**
* Kafka storage behavior updated so persistent volumes are automatically
removed when claims are deleted, changing storage lifecycle for
deployments.

* **Tests**
* End-to-end cleanup adjusted to remove the Kafka resource and verify
volumes are reclaimed automatically, adding waits to confirm PVC binding
and removal.

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hack/e2e-apps/kafka.bats

@@ -47,10 +47,15 @@ EOF
   kubectl wait kafkas -n tenant-test $name --timeout=300s --for=condition=ready
   timeout 60 sh -ec "until kubectl -n tenant-test get pvc data-kafka-$name-zookeeper-0; do sleep 10; done"
   kubectl -n tenant-test wait pvc data-kafka-$name-zookeeper-0 --timeout=50s --for=jsonpath='{.status.phase}'=Bound
+  timeout 60 sh -ec "until kubectl -n tenant-test get pvc data-kafka-$name-zookeeper-1 >/dev/null 2>&1; do sleep 2; done"
+  kubectl -n tenant-test wait pvc data-kafka-$name-zookeeper-1 --timeout=50s --for=jsonpath='{.status.phase}'=Bound
   timeout 40 sh -ec "until kubectl -n tenant-test get svc kafka-$name-zookeeper-client -o jsonpath='{.spec.ports[0].port}' | grep -q '2181'; do sleep 10; done"
   timeout 40 sh -ec "until kubectl -n tenant-test get svc kafka-$name-zookeeper-nodes -o jsonpath='{.spec.ports[*].port}' | grep -q '2181 2888 3888'; do sleep 10; done"
   timeout 80 sh -ec "until kubectl -n tenant-test get endpoints kafka-$name-zookeeper-nodes -o jsonpath='{.subsets[*].addresses[0].ip}' | grep -q '[0-9]'; do sleep 10; done"
-  kubectl -n tenant-test delete kafka.apps.cozystack.io $name
-  kubectl -n tenant-test delete pvc data-kafka-$name-zookeeper-0
-  kubectl -n tenant-test delete pvc data-kafka-$name-zookeeper-1
+  kubectl -n tenant-test delete kafka.apps.cozystack.io $name --timeout=2m
+  # Strimzi reclaims ZooKeeper PVCs automatically when deleteClaim is true on
+  # the persistent-claim storage. Verify they disappear instead of issuing a
+  # manual kubectl delete, which would mask a regression in the operator.
+  timeout 60 sh -ec "while kubectl -n tenant-test get pvc data-kafka-$name-zookeeper-0 >/dev/null 2>&1; do sleep 2; done"
+  timeout 60 sh -ec "while kubectl -n tenant-test get pvc data-kafka-$name-zookeeper-1 >/dev/null 2>&1; do sleep 2; done"
 }

packages/apps/kafka/templates/kafka.yaml

@@ -73,7 +73,7 @@ spec:
       {{- with .Values.kafka.storageClass }}
       class: {{ . }}
       {{- end }}
-      deleteClaim: false
+      deleteClaim: true
     metricsConfig:
       type: jmxPrometheusExporter
       valueFrom: