Support using infraStorageClassEnforcement.allowAll on Kubevirt HCP clusters

If manual mappings are not specified in the hostedcluster (.spec.platform.kubevirt.storageDriver)

spec:
  platform:
    kubevirt:
      baseDomainPassthrough: false
      generateID: xmwz2gh5j6
    type: KubeVirt

and we support setting:

infraStorageClassEnforcement:
  allowAll: true

then cluster administrators can:
* Add and remove guest storage classes as needed
* Perform in‑guest data migrations using standard tooling
* Avoid disruptive and unnecessary cluster rebuilds

No new functionality is required — only a supported way to configure an existing control. Currently this is hardcoded in https://github.com/openshift/hypershift/blob/195ba09e55a6f62e30d93d656fa0dcb6c29ea637/control-plane-operator/controllers/hostedcontrolplane/v2/csi/kubevirt/config.go#L95

In this model, allowing administrators to manage storage classes

This solution allows the customer to manually manage storage as required, without having to use or modify the mappings which were denied in RFE-7560.

* Tenants run persistent, long‑lived workloads
* Storage backends must change over time (array refresh, migration, vendor change)

Current Red Hat guidance requires rebuilding guest clusters when infra storage classes change. Forcing tenants to rebuild clusters to accommodate storage lifecycle events is not an option and makes Hosted OpenShift unsuitable for real‑world enterprise use.

Storage classes must be addable and removable in guest clusters without requiring mandatory cluster rebuilds.

Requiring tenant cluster rebuilds for storage backend changes is operationally and commercially unacceptable.

kubevirt-csi
HCP