Add CRD schema tests

[everettraven]

As mentioned in operator-framework/catalogd#225 (review) we should add some form of CRD schema tests to ensure that the schemas have the proper validations and properly catch cases like operator-framework/catalogd#224

[github-actions]

Issues go stale after 90 days of inactivity. If there is no further activity, the issue will be closed in another 30 days.