Add image label with latest HC version supported by the operator

Multiple consumers have not realised a newer version of a CPO (spec.release) is not guaranteed to work with an older HO.

This is stated here https://hypershift-docs.netlify.app/reference/versioning-support/

but empiric evidences like OCM integration are telling us this is not enough.

We already deploy a CM in the HO namespace with the HC supported versions.

Additionally we can add an image label with latest HC version supported by the operator so you can quickly docker inspect...