Allow path-like objects in fnmatch.filter on POSIX platforms #123135

In fnmatch.filter, it says that

# normcase on posix is NOP. Optimize it away from the loop.

This is not the case. os.path.normcase actually calls os.fspath on POSIX, meaning that path-like objects are allowed. Thus, we cannot optimize it away from the loop. I'll update #123122 accordingly.

Related: #123122 (comment)

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-123135: add support for path-like objects in fnmatch.filter on POSIX platforms #123122