Fix PVC finalizer not removed due to broken VolumeSnapshots

[vasumahalingam-nutanix]

What type of PR is this?

/kind bug

What this PR does / why we need it:

Fixes a bug where a PVC’s finalizer snapshot.storage.kubernetes.io/pvc-as-source-protection is not removed when there are broken or misconfigured VolumeSnapshots that reference the PVC but never transition to ReadyToUse.

The snapshot controller currently considers any VolumeSnapshot with ReadyToUse == false as blocking PVC deletion — even if the snapshot is invalid and has already failed.

This patch ensures the controller only considers:

• VolumeSnapshots with ReadyToUse == false, and
• that still retain the pvc-as-source-protection finalizer

This avoids permanently stuck PVCs when broken snapshots linger in the namespace.

Which issue(s) this PR fixes:
Fixes #1305

Special notes for your reviewer:

• The change preserves the protective behavior for in-progress snapshots.
• The PVC can now be deleted once only broken snapshots remain, and they no longer hold the finalizer.

Does this PR introduce a user-facing change?:

Fix: PVC finalizer `snapshot.storage.kubernetes.io/pvc-as-source-protection` is now removed even if other VolumeSnapshots are stuck in a failed state, as long as those snapshots no longer hold the finalizer.

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: vasumahalingam-nutanix
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[k8s-ci-robot]

Hi @vasumahalingam-nutanix. Thanks for your PR.

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