[3.12] gh-119819: Conditional skip of logging tests that require multiprocessing subprocess support (GH-120476) (#120532)

gh-119819: Conditional skip of logging tests that require multiprocessing subprocess support (GH-120476)

Skip tests that require multiprocessing subprocess support.
(cherry picked from commit 92f6d400f76b6a04dddd944568870f689c8fab5f)

Co-authored-by: Russell Keith-Magee <russell@keith-magee.com>