Statefulset volumeClaimTemplates labels not properly merged after patch

### What happened?

I encountered a case were label pairs are not properly merged after applying a patch.

### What did you expect to happen?

I expected source labels pair to be still present in the volumeClaimTemplates[]/metadata/labels.

### How can we reproduce it (as minimally and precisely as possible)?

```yaml
# source/kustomization
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- sts.yaml
labels:
- pairs:
app.kubernetes.io/name: vmcluster
app.kubernetes.io/stack: victoriametrics
includeSelectors: true
includeTemplates: true
```

```yaml
# source/sts.yaml
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
labels:
app.kubernetes.io/component: vmstorage
name: vmstorage
spec:
template:
metadata:
labels:
app.kubernetes.io/component: vmstorage
spec:
containers:
- name: vmstorage
image: quay.io/victoriametrics/vmstorage:v1.128.0-cluster
updateStrategy:
rollingUpdate:
partition: 0
type: RollingUpdate
volumeClaimTemplates:
- apiVersion: v1
kind: PersistentVolumeClaim
metadata:
labels:
app.kubernetes.io/component: vmstorage
name: vmstorage-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 50Gi
storageClassName: gp3
volumeMode: Filesystem
```

```yaml
# kustomization
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- source
labels:
- pairs:
app.kubernetes.io/instance: vmcluster-internal
includeSelectors: true
includeTemplates: true
patches:
- path: patch.yaml
```

```yaml
# patch.yaml
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
labels:
app.kubernetes.io/component: vmstorage
name: vmstorage
spec:
volumeClaimTemplates:
- apiVersion: v1
kind: PersistentVolumeClaim
metadata:
labels:
app.kubernetes.io/component: vmstorage
name: vmstorage-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 600Gi
storageClassName: gp3
volumeMode: Filesystem
```

### Expected output

```yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
labels:
app.kubernetes.io/component: vmstorage
app.kubernetes.io/instance: vmcluster-internal
app.kubernetes.io/name: vmcluster
app.kubernetes.io/stack: victoriametrics
name: vmstorage
spec:
...
volumeClaimTemplates:
- apiVersion: v1
kind: PersistentVolumeClaim
metadata:
labels:
app.kubernetes.io/component: vmstorage
app.kubernetes.io/instance: vmcluster-internal
app.kubernetes.io/name: vmcluster
app.kubernetes.io/stack: victoriametrics
name: vmstorage-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 600Gi
storageClassName: gp3
volumeMode: Filesystem
```

### Actual output

```yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
labels:
app.kubernetes.io/component: vmstorage
app.kubernetes.io/instance: vmcluster-internal
app.kubernetes.io/name: vmcluster
app.kubernetes.io/stack: victoriametrics
name: vmstorage
spec:
...
volumeClaimTemplates:
- apiVersion: v1
kind: PersistentVolumeClaim
metadata:
labels:
app.kubernetes.io/component: vmstorage
app.kubernetes.io/instance: vmcluster-internal
name: vmstorage-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 600Gi
storageClassName: gp3
volumeMode: Filesystem
```

### Kustomize version

v5.7.1

### Operating system

MacOS

Reproduce the issue with the shown source/sts.yaml, kustomization, and patch.yaml inputs using Kustomize v5.7.1, then compare the generated StatefulSet with the expected output. Trace how labels are merged on StatefulSet volumeClaimTemplates after the patch; done means both source label pairs and the outer kustomization label remain in the template metadata.

Written by the indexing model from the issue text.