[stdlib][tarfile] Change errorlevel type from int | None to int

[guoci]

Docs: https://docs.python.org/dev/library/tarfile.html#tarfile.TarFile.errorlevel
src: https://github.com/python/cpython/blob/e6bfe4d8869e046a91d091611d3c7b5dccdaf0d6/Lib/tarfile.py#L1709

>>> import tarfile
>>> tarfile.TarFile("somefile", 'w').errorlevel
1
>>> ```

[github-actions]

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