Adopt PEP 517 tooling for Python packages

Summary

Replace setup.py with PEP 517 tooling (python-build/python-installer) for all Python packages where this approach is viable.

Motivation

There are two main points.

1. Direct setup.py calls are deprecated

The setuptools upstream has deprecated direct setup.py calls, and plans to remove support for them in the future. Please see setuptools #2088 and setuptools #2080 for more context.

2. setup.py install calls install old-style Python metadata

The metadata installed by setup.py install is the old-style "egg" format (.egg-info). Is is essentially implementation-defined by setuptools and has been replaced by a standardized format (.dist-info). By moving to the PEP 517 tooling, we will be using the wheel format, which has the standardized metadata.

Specification

The change consists of replacing setup.py invocations with the python-build and python-installer tools.

Essentially replacing

python setup.py build
python setup.py install --root="$pkgdir" --optimize=1

with

python -m build --wheel --no-isolation
python -m installer --destdir="$pkgdir" dist/*.whl

You can find more information in the Python packaging guidelines.

This would naturally only serve as a general guideline, packages that need an alternative approach can still do so, but are recommended to stay as close as the guidelines as reasonably possible.

Drawbacks

This change affects a big number of packages, so it will require some work per part of the maintainers, but it can be done incrementally as packages are updated.

Unresolved Questions

None, I think.

Alternatives Considered

I don't think there is currently any viable alternative solution for the issues presented.