PEP639 formatting

[bkmgit]

🤔 What's changed?

Updated how license metadata is specified in pyproject.toml file

⚡️ What's your motivation?

Be compliant with PEP639

🏷️ What kind of change is this?

• 🏦 Refactoring/debt/DX (improvement to code design, tooling, etc. without changing behaviour)

♻️ Anything particular you want feedback on?

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.

[kieran-ryan]

Much appreciated @bkmgit - we're in the process of updating our Python packages to the latest standards and tooling - so this is most helpful on the two outstanding packages - thank you!

Change was added in the poetry-specific tool.poetry though also required transformation to the standardised PEP 621 project specification in order to install and build the package; and to pin the poetry core build backend above the recently released v2.2.0 which implements required support for this change. Retained the classifier for now, matching ruff - may revisit when migrating to uv from poetry. Appreciated! Thanks again!

c.c. @mpkorstanje