volumeAttributesClassName in volumeClaimTemplate is not applied to existing PVCs

What happened

I set volumeAttributesClassName on vlstorage.storage.volumeClaimTemplate.spec in a VLCluster. The operator noticed the change and recreated the StatefulSet, and the new StatefulSet carries the field. The three existing PVCs were left as they were, so the volumes kept their original IOPS and throughput.

Operator v0.65.0, Kubernetes 1.36, aws-ebs-csi-driver v1.44.0.

What I expected

updateSTSPVC already lists the live PVCs and reconciles them against the template, so I expected the class name to be carried over the way a size change is.

Why it does not

modifyPVC in internal/controller/operator/factory/reconcile/statefulset_pvc_expand.go returns early when the storage request is unchanged, and Spec.Resources is the only spec field it ever writes.

Suggested change

Copy the field when it is set and differs:

vacChanged := newObj.Spec.VolumeAttributesClassName != nil &&
    !ptr.Equal(existingObj.Spec.VolumeAttributesClassName, newObj.Spec.VolumeAttributesClassName)

and let that count towards the early return. The nil check is needed because clearing the field is rejected once a class has taken effect.

Users who do not set the field are unaffected, since both sides stay nil and the comparison is false.

I am happy to open a PR if you would take it.