[3.13] gh-117657: Skip tests that use threads after fork (GH-122194) (#122198)

These tests fail when run under thread sanitizer due to the use of fork
and threads.
(cherry picked from commit 64e221d7ada8f6c20189035c7e81503f4c914f04)

Co-authored-by: Sam Gross <colesbury@gmail.com>