[3.12] gh-120268: Prohibit passing ``None`` to ``_pydatetime.date.fromtimestamp`` (GH-120269) (GH-120283)

This makes the pure Python implementation consistent with the C implementation.
(cherry picked from commit 34f5ae69fe9ab0f5b23311d5c396d0cbb5902913)

Co-authored-by: Kirill Podoprigora <kirill.bast9@mail.ru>