Fixes

• 👷 Switch to dynamic versioning with pdm build system. PR #19 by @svlandeg.

Upgrades

• ⬆ Bump ruff from 0.14.1 to 0.14.3. PR #17 by @dependabot[bot].

Internal

• ➕ Add typing-extensions to test requirements for Python < 3.9. PR #12 by @musicinmybrain.
• ⬆ Bump actions/upload-artifact from 4 to 5. PR #14 by @dependabot[bot].
• ⬆ Bump actions/download-artifact from 5 to 6. PR #13 by @dependabot[bot].