Incus: Nil-pointer dereference in createDependentVolumesFromBackup on disk.{Volume,VolumeSnapshots,Pool}

Summary backend.createDependentVolumesFromBackup in internal/server/storage/backend.go contains a cluster of unguarded pointer derefs on every dependent-volume entry's VolumeSnapshotsi, Volume, and Pool sub-fields. An authenticated user with cancreateinstances permission on any project can crash...