Fix license deprecation warning in pyproject.toml (#49)fix: replace table license with SPDX in pyproject.toml (#49)

[V1rg1lee]

Summary

This PR corrects the SetuptoolsDeprecationWarning warning reported in issue #49 :

project.license as a TOML table is deprecated…

Why

As of PEP 639 (early 2025), Python packaging moved to a clearer, unambiguous license metadata format:

• Before: license declared as a TOML table with keys like text and file, which was inconsistent and hard for tools to validate.
• After: a single SPDX expression string (license = "BSD-2-Clause") plus a license-files list.
  Setuptools ≥ 77 now requires this new format and will warn (or error) on the old table style. This change ensures compatibility with the current Python packaging ecosystem and automatic license validation.

Changes made

• Removed license = { ... } table from [project].
• Added license = "BSD-2-Clause" and license-files = ["LICENSE"] in [project].
• Removal of classifier "License :: OSI Approved :: BSD License" (compliant with PEP 639)

How to test

1. Clone the repository and switch to this branch
2. Install a virtual environment: python -m venv env and source env/bin/activate (on Linux).
3. Install in dev: pip install -e .[dev]
4. Builder: python -m build → no more warnings or errors
5. Run the test suite: env/bin/python -m pytest → everything goes green

Linked to

Closes #49