Further modernization of the build backend to reduce `setup.py` usage

Creating an issue to capture the internal discussions.

Currently both cuda.bindings and cuda.core use setuptools as the build backend and have a mixture of pyproject.toml static declarations and setup.py dynamic logics. We have two choices here:

• Keep setuptools but further reduce the amount of code in setup.py:
  • This seems to become possible with recent setuptools, where Cython extensions can now be declared in pyproject.toml.
• Switch to use scikit-build-core:
  • This has the benefit of reusing CUDA discovery mechanism (FindCUDAToolkit) and other nice build system features provided by CMake (see the relevant discussion in #46).
  • The potential downside is to maintain a custom CMakeLists.txt which is arguably a burden for non-C++ (=C & Python) oriented developers. Our Cython extensions are very simple to build.
    • However, this might become necessary once we start integrating some features from cudax::, e.g. #528.

Commencez par comparer les configurations actuelles de pyproject.toml et setup.py pour cuda.bindings et cuda.core, puis lisez la discussion liée dans #46. Évaluez si les versions récentes de setuptools peuvent déclarer les extensions Cython ou si scikit-build-core et un CMakeLists.txt sont nécessaires, en tenant compte également des considérations futures concernant cudax:: dans #528. Le travail sera considéré comme terminé lorsque le projet aura convenu d’une orientation pour le backend de build et de son périmètre.