bpo-44524: Fix cryptic TypeError message when trying to subclass special forms in `typing` (GH-27710)


This was a Python 3.9 regression.
(cherry picked from commit a3a4d20d6798aa2975428d51f3a4f890248810cb)

Co-authored-by: Yurii Karabas <1998uriyyo@gmail.com>
3 files changed