Switch from setup.py to pyproject.toml

[Valentin-Laurent]

Context
MAPIE is using setuptools (with setup.py) to build its distribution. This will soon have consequences, as pip 25.0 will enforce more modern tooling.

We should switch to pyproject.toml. This ressource may be interesting.

Describe the bug
For example, installing MAPIE 0.9 in dev mode throws a pip deprecation warning.

To Reproduce
Clone the repo then run pip install -e .

Stacktrace

DEPRECATION: Legacy editable install of MAPIE==0.9.0 from file:///Users/vlaurent/code/pro/MAPIE/MAPIE (setup.py develop) is deprecated. pip 25.0 will enforce this behaviour change. A possible replacement is to add a pyproject.toml or enable --use-pep517, and use setuptools >= 64. If the resulting installation is not behaving as expected, try using --config-settings editable_mode=compat. Please consult the setuptools documentation for more information. Discussion can be found at https://github.com/pypa/pip/issues/11457
  Running setup.py develop for MAPIE
Successfully installed MAPIE-0.9.0

Additional info
I got this email when uploading MAPIE to TestPyPi:

In the future, PyPI will require all newly uploaded source distribution filenames to comply with PEP 625. Any source distributions already uploaded will remain in place as-is and do not need to be updated.

Specifically, your recent upload of 'MAPIE-1.0.0a1.tar.gz' is incompatible with PEP 625 because it does not contain the normalized project name 'mapie'.

In most cases, this can be resolved by upgrading the version of your build tooling to a later version that supports PEP 625 and produces compliant filenames.