bpo-16086: Fix PyType_GetFlags() documentation (GH-10758) (GH-10789)

PyType_GetFlags() return type is unsigned long, not long.
(cherry picked from commit 9fbcfc08e5814d7aa9287740187e461425a99f67)

Co-authored-by: Eddie Elizondo <eduardo.elizondorueda@gmail.com>
1 file changed