[3.14] gh-146615: Fix crash in __get__() for METH_METHOD descriptors with invalid type argument (GH-146634) (GH-146647)

(cherry picked from commit 72d29ea363f1515115753653aeca735a1a817a7f)

Co-authored-by: sunmy2019 <59365878+sunmy2019@users.noreply.github.com>