[hibernate-dev] HHH-10487 - @Incubating annotation

[Steve Ebersole]

Per HHH-10487[1], I want to add an @Incubating annotation to mark APIs that
are still incubating.  Specifically, what do y'all think of
`java.lang.annotation.RetentionPolicy#CLASS` versus
`java.lang.annotation.RetentionPolicy#RUNTIME`?

[1] https://hibernate.atlassian.net/browse/HHH-10487