[3.13] gh-125243: Fix ZoneInfo data race in free threading build (GH-125281) (gh-125414)

Lock `ZoneInfoType` to protect accesses to `ZONEINFO_STRONG_CACHE`.
Refactor the `tp_new` handler to use Argument Clinic so that we can just
use `@critical_section` annotations on the relevant functions.

Also use `PyDict_SetDefaultRef` instead of `PyDict_SetDefault` when
inserting into the `TIMEDELTA_CACHE`.
(cherry picked from commit f1d33dbddd3496b062e1fbe024fb6d7b023a35f5)

Co-authored-by: Sam Gross <colesbury@gmail.com>