Bug report

Bug description:

Follow-up to#90817.

In summary, withoutgetdetfaultlocale, tools that rely on POSIX locales cannot reliably get the same information fromgetlocale orsetlocale on Windows.

For example, Linux will return something like 'en_AU'. But on Windows,getlocale will return something like 'English_Australia'.

CPython versions tested on:

3.12, 3.13

Operating systems tested on:

Windows, Linux