Continuing work towards #8988.
The first five commits were created using stubdefaulter on various Python versions; the following commits were all created manually by me to fix various problems. The main things this adds that weren't present in #9501 are:
- Defaults in Windows-only modules and Windows-only branches (because I'm running a Windows machine)
- Defaults in non-py311 branches
- Defaults for float parameters
- Defaults for overloads
* Replace all uses of StrPath, BytesPath, and AnyPath in Python 2 stubs.
* Add StrOrBytesPath as preferred alias for AnyPath.
* Replace all remaining AnyPath instances with StrOrBytesPath.
* Mark AnyPath as obsolete.
Part of #5470
