[3.12] gh-113267: Revert "gh-106584: Fix exit code for unittest in Python 3.12 (GH-106588)" (GH-114470) (GH-114994)

This reverts commit 8fc071345b50dd3de61ebeeaa287ccef21d061b2.
(cherry picked from commit ecabff98c41453f15ecd26ac255d531b571b9bc1)

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