`zipfile.ZipFile.writestr()` raises `AttributeError` instead of accepting `os.PathLike` objects (e.g. `pathlib.Path`)

Bug report

Bug description:

Unlike ZipFile.write() (which accepts os.PathLike objects such as pathlib.Path for both its filename and arcname arguments), ZipFile.writestr() fails when passed a PathLike object as its zinfo_or_arcname parameter.

Instead of converting it to a string using os.fspath() (as expected by modern standard library conventions), it attempts to call .find(chr(0)) directly on the path object, resulting in an immediate AttributeError.

Repro:

import zipfile
import pathlib
import io
z = zipfile.ZipFile(io.BytesIO(), 'w')
# Passes a pathlib.Path instead of a raw string
z.writestr(pathlib.Path('foo.txt'), b'hello')

Traceback:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File ".../zipfile/__init__.py", line 2020, in writestr
    zinfo = ZipInfo(zinfo_or_arcname)._for_archive(self)
            ^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../zipfile/__init__.py", line 455, in __init__
    filename = _sanitize_filename(filename)
  File ".../zipfile/__init__.py", line 410, in _sanitize_filename
    null_byte = filename.find(chr(0))
                ^^^^^^^^^^^^^
AttributeError: 'PosixPath' object has no attribute 'find'

CPython versions tested on:

3.14

Operating systems tested on:

macOS

從 zipfile/init.py 中的 ZipFile.writestr()、ZipInfo.init() 和 _sanitize_filename() 開始，然後執行 issue 中使用 pathlib.Path 的重現步驟。完成的標準是 writestr() 接受像 pathlib.Path 這樣的 os.PathLike 物件而不引發 AttributeError，同時保留現有的字串行為。