[3.13] gh-123275: Add tests for `PYTHON_GIL=1` and `-Xgil=1` (gh-123754) (gh-123755)

gh-123275: Add tests for `PYTHON_GIL=1` and `-Xgil=1` (gh-123754)
(cherry picked from commit fe24b718d231317516f96f896e7c17a4166f25a7)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>