vm-instance: efiPersistent description claims the VM loses live migration on RWO storage #4420

The firmware.efiPersistent description in vm-instance says the VM loses live migration on default storage, and that is no longer true. The text reads "On default RWO storage the VM is node-pinned (no live-migration)" in packages/apps/vm-instance/values.yaml:30, and the generated README.md and values.schema.json carry the same sentence.

KubeVirt has migrated ReadWriteOnce backend storage since v1.4 (kubevirt/kubevirt#12629). It creates a new state PVC on the target and copies the EFI/TPM state during the migration. The v1.5.4 changelog entry for #3154 says the same and records that a persistent-firmware VM on the default replicated class reports LiveMigratable=True. That was the reason #3005 was reverted.

A user reading the field today would think enabling it costs them live migration and node drains, and may leave Secure Boot key persistence off for that reason. The fix is to drop the sentence, or replace it with a note that the state PVC is copied on migration, then regenerate the README and schema.