Docker compose doesn't work on ARM

[fitzthum]

It looks like the coco-keyprovider binary is not supported on ARM, so docker compose explodes on startup on that platform. We don't really even use the cooc-keyprovider. Maybe we should just delete that part, or fix the build (which is actually in guest-components).

[Xynnn007]

Looks like the way to encrypt image officially documented is not relying on the coco provider in trustee? https://confidentialcontainers.org/docs/features/encrypted-images/

If this is the reality, I agree to delete this part.

[fitzthum]

@bpradipt any thoughts on this one? Does the operator have the keyprovider?