shutil.which cannot return PathLike, and fails with cmd: PathLike on Windows Python < 3.12

[Avasam]

As found on Python's Discord: https://discord.com/channels/267624335836053506/891788761371906108/1346539455267213372

Linux:

>>> import shutil
>>> from pathlib import Path
>>> which(Path("bash"))
'/usr/bin/bash'

Python 3.10, Windows:

>>> import shutil
>>> from pathlib import Path
>>> shutil.which(Path("python"))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Avasam\AppData\Local\Programs\Python\Python310\lib\shutil.py", line 1492, in which
    if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
  File "C:\Users\Avasam\AppData\Local\Programs\Python\Python310\lib\shutil.py", line 1492, in <genexpr>
    if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
AttributeError: 'WindowsPath' object has no attribute 'lower'. Did you mean: 'owner'?

Python 3.12 & 3.13, Windows:

>>> import shutil
>>> from pathlib import Path
>>> shutil.which(Path("python"))
'E:\\Program Files\\uv\\cache\\archive-v0\\9TtCCyEjyO6hv113bBovk\\Scripts\\python.EXE'

Oh and all cases I found, folders return None

Relevant CPython PR (I think) that fixed Path on Windows: python/cpython#103179

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉