Remove skip for crypto unit test in darwin

We want to undo https://github.com/aws/eks-anywhere/pull/3262 as soon as Go makes the appropriate fix here https://github.com/golang/go/issues/52010. Currently slated for `1.20` release, so when we upgrade to that version we should be able to verify if the same type is returned as for linux.

Start by reviewing pull request #3262 and the linked Go issue #52010 to understand the Darwin crypto test workaround. Locate the skipped unit test, then verify it with the Go 1.20 upgrade on Darwin and Linux; done means the skip can be removed and both platforms return the same type.

Written by the indexing model from the issue text.