chore(deploy): add missing apiVersion and kind for PVC (#716)

- Fixes a deployment issue with CD tools like ArgoCD.
- apiVersion and kind not set in source, causing drift.
- Ensures consistent state across deployments.

Signed-off-by: kahirokunn <okinakahiro@gmail.com>

deploy/etcd/etcd-cluster.yaml

@@ -104,7 +104,9 @@ spec:
               fieldRef:
                 fieldPath: metadata.namespace
   volumeClaimTemplates:
-  - metadata:
+  - apiVersion: v1
+    kind: PersistentVolumeClaim
+    metadata:
       name: data
     spec:
       accessModes: ["ReadWriteOnce"]