[3.12] gh-113781: Silence AttributeError in warning module during Python finalization (GH-113813) (GH-113873)

The tracemalloc module can already be cleared.
(cherry picked from commit 0297418cacf998e778bc0517aa11eaac827b8c0f)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>