[3.11] gh-109295: Clean up multiprocessing in test_asyncio and test_compileall (GH-109298) (#109302)

gh-109295: Clean up multiprocessing in test_asyncio and test_compileall (GH-109298)

test_asyncio and test_compileall now clean up multiprocessing by
calling multiprocessing _cleanup_tests(): explicitly clean up
resources and stop background processes like the resource tracker.
(cherry picked from commit 09ea4b8706165fd9474165090a0ba86509abd6c8)

Co-authored-by: Victor Stinner <vstinner@python.org>