bpo-46491: Allow Annotated on outside of Final/ClassVar (GH-30864)

We treat Annotated type arg as class-level annotation. This exempts it from checks against Final and ClassVar in order to allow using them in any nesting order.

Automerge-Triggered-By: GH:gvanrossum
(cherry picked from commit e1abffca45b60729c460e3e2ad50c8c1946cfd4e)

Co-authored-by: Gregory Beauregard <greg@greg.red>