CD plugin: Unprepare even when claim has been force-deleted

[jgehrcke]

A sufficiently determined user might remove a ResourceClaim before the corresponding resources are properly deallocated/unprepared/torn-down.

In that case, we want the system to not go into a bad state.

See #332 (comment)

[jgehrcke]

The unprepare code path needs claim details but shouldn't rely on being able to fetch them from the API server. Feed details from local checkpointing data instead. This is about e.g.

k8s-dra-driver-gpu/cmd/compute-domain-kubelet-plugin/device_state.go

Line 436 in d17cfcf

for _, result := range claim.Status.Allocation.Devices.Results {

[jgehrcke]

Let's consider this 'done', now that #342 landed.