Notes:
- setup.py is still needed for versioneer support.
- versioneer.py vendoring is needed for Conda packaging (so that the
  version can be available to meta.yaml before the building itself).

related_to #411

Notes:
- the version is hard-coded in the khiops/__init__.py file and not in
  pyproject.toml, because pyproject.toml is not accessible at runtime
  for an installed package
- conda-build does not support pyproject.toml-style dynamic versions,
  hence the version has to be hard-coded in conda/meta.yaml as well
- when moving to conda-forge, the version would have to be hard-coded
  anyway
- the khiops/__init__.py vs conda/meta.yaml version coherence is checked
  in the conda package building and testing workflow.