`Distribution.files` does not show files with absolute RECORD entries on Windows with Python 3.10 and 3.11

If an installed distribution contains absolute paths in the RECORD file, Distribution.files is missing these files. (installer writes absolute paths for executable scripts on Windows since https://github.com/pypa/installer/pull/286.)

To reproduce:

sampleproject/
├── sample/
│   ├── __init__.py
│   └── __main__.py
└── pyproject.toml

[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"

[project]
name = "sample"
version = "0.1"

[project.scripts]
sample = "sample:__main__"

python -m venv build-venv
build-venv\Scripts\python.exe -m pip install build
build-venv\Scripts\python.exe -m build sampleproject

Install the built wheel with installer and display the distribution files:

python -m venv test-venv
test-venv\Scripts\python.exe -m pip install installer importlib-metadata
test-venv\Scripts\python.exe -m installer sampleproject\dist\sample-0.1-py3-none-any.whl
test-venv\Scripts\python.exe -c "from pprint import pprint; from importlib_metadata import distribution; pprint(distribution('sample').files)"

When using Python 3.12 or later to install the wheel and display the files the correct output is:

[PackagePath('sample-0.1.dist-info/METADATA'),
PackagePath('sample-0.1.dist-info/RECORD'),
PackagePath('sample-0.1.dist-info/WHEEL'),
PackagePath('sample-0.1.dist-info/entry_points.txt'),
PackagePath('sample-0.1.dist-info/top_level.txt'),
PackagePath('C:/temp/test-uninstall/test-venv/Scripts/sample.exe'),
PackagePath('sample/__init__.py'),
PackagePath('sample/__main__.py')]

When using Python 3.11 or 3.10 to install the wheel and display the files the executable script is missing:

[PackagePath('sample-0.1.dist-info/METADATA'),
PackagePath('sample-0.1.dist-info/RECORD'),
PackagePath('sample-0.1.dist-info/WHEEL'),
PackagePath('sample-0.1.dist-info/entry_points.txt'),
PackagePath('sample-0.1.dist-info/top_level.txt'),
PackagePath('sample/__init__.py'),
PackagePath('sample/__main__.py')]

The reason is the following difference in path operations:

>C:\python311\python.exe -c "from pathlib import Path, PurePosixPath; print(Path('C:/a') / PurePosixPath('C:/b/c'))"
C:\a\b\c
 
>C:\python312\python.exe -c "from pathlib import Path, PurePosixPath; print(Path('C:/a') / PurePosixPath('C:/b/c'))"
C:\b\c

This issue can be worked around by converting the PurePosixPath to str first:

>C:\python311\python.exe -c "from pathlib import Path, PurePosixPath; print(Path('C:/a') / str(PurePosixPath('C:/b/c')))"
C:\b\c

Would you be open to such a fix in https://github.com/python/importlib_metadata/blob/f09a4bd87e3ed8f8c3bda7074bc8f7b0dfb94d72/importlib_metadata/__init__.py#L1046 ?

importlib_metadata/init.py の1046行目付近から始め、Windows上でPython 3.10または3.11を使ってサンプルwheelのシナリオを再現します。絶対パスのRECORDエントリの処理を確認し、その後、Python 3.12以降と同様にDistribution.filesに実行可能ファイルのパスが含まれていることを検証します。