`os.path.realpath` raises a `ValueError` when path contains a null byte

Bug report

Bug description:

import os
os.path.realpath("\x00")  # raises unexpected ValueError

The ValueError is initially raised by os.lstat.

This behavior is inconsistent with other path operations catching the ValueError raised by os.lstat:
os.path.lexsists: https://github.com/python/cpython/blob/main/Lib/genericpath.py#L30
os.path.exists: https://github.com/python/cpython/blob/main/Lib/genericpath.py#L20
os.path.islink: https://github.com/python/cpython/blob/main/Lib/genericpath.py#L64
os.path.ismount: https://github.com/python/cpython/blob/main/Lib/posixpath.py#L197
os.path.ismount: https://github.com/python/cpython/blob/main/Lib/posixpath.py#L213

CPython versions tested on:

3.10, CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-117573
• gh-134189
• gh-134265
• gh-134266
• gh-142415

使用 os.path.realpath 重现空字节情况，然后检查 Lib/genericpath.py 和 Lib/posixpath.py 中对 os.lstat 的处理，尤其是所引用的 exists、lexists、islink 和 ismount 实现。当 realpath 以与这些路径操作一致的方式处理 ValueError 时，即表示完成；开始前请先审阅链接的 PR。