[3.13] gh-117398: Add datetime C-API type check test for subinterpreters (gh-120463)

Check if the DateTime C-API type matches the datetime.date type on main and shared/isolated subinterpreters.

(cherry picked from commit 50a389565aa0b480792ed06a2ab56fb5a72fc2d8, AKA gh-119604)

Co-authored-by: neonene <53406459+neonene@users.noreply.github.com>