datetime does not support timestamps after 2038 on 32-bit

Bug report

cpython on 32-bit platforms cannot handle dates beyond 2038-01-19

python3.10 -c 'import datetime; datetime.datetime.fromtimestamp(3000000000)'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
OverflowError: timestamp out of range for platform time_t

Your environment

• CPython versions tested on: 3.8, 3.9, 3.10
• Operating system and architecture: openSUSE-Tumbleweed 20230110 i586

This comes from
https://github.com/python/cpython/blob/8e9d08b0/Modules/_datetimemodule.c#L4982
https://github.com/python/cpython/blob/8e9d08b0/Python/pytime.c#L173

These could use __time64_t if available or we compile everything with __TIMESIZE=64

首先阅读 Modules/_datetimemodule.c 中第 4982 行附近以及 Python/pytime.c 中第 173 行附近的时间戳处理代码，同时考虑报告中的 32 位 openSUSE 环境。确定实现如何在可用时使用 64 位时间支持，然后验证 datetime.fromtimestamp(3000000000) 在 32 位平台上能够成功执行，且不会出现报告中的溢出问题。