JPA subsystem should fail deployment if ValidationMode.CALLBACK is configured but the BV capability is not present

This is a follow-on to https://github.com/wildfly/wildfly/pull/13444 / WFLY-13726. That fix is about applying logic consistently in both places where PersistenceUnitServiceHandler integrates with BV. But I suspect the existing handling isn't correct in the case where ValidationMode.CALLBACK is configured. The javadoc for that enum value says "The persistence provider must perform the lifecycle event validation. It is an error if there is no Bean Validation provider present in the environment." But I think our handling is ignoring that if the BV capability is not present.