Optimise Python tooling infrastructure

[kieran-ryan]

🤔 What's changed?

• uv package management (and cache) - over poetry and pre-commit
• uv Python management (and cache) - over setup-python
• uv build backend over poetry
• ruff linter and formatter over black, isort and flake8
• Renovate automated dependency updates for pre-commit
• Drop end-of-line Python 3.8 and 3.9 and add latest stable 3.14
  • Python 3.10+ native type hints e.g. list over typing.List
• Closes #29

⚡️ What's your motivation?

• Improve CI performance

  • 61.5% reduction in runner uptime - saving $158.11 and 7348 runner minutes compared to 8.79 days total runner usage for this workflow over the past year (assuming GitHub Actions pricing)
  • 85.3% faster workflow - saving 2.14 days where the workflow would otherwise be running, across a thousand runs
  • 64% faster average job execution - continuous Python feedback In 6s

  Metric	Previous	Now	Delta	% Change
  Total Runner Time	18m 27s (1107s)	13m 15s (795s)	-5m 12s (-312s)	-28.2%
  Total Python Test Runner Time	4m 41s (301s)	1m 56s (116s)	-3m 5s (-185s)	-61.5%
  Python Test Workflow Duration	6m 47s (407s)	1m 0s (60s)	-5m 47s (-347s)	-85.3%
  Python Test Fastest Job	18s	6s	-12s	-67%
  Python Test Average Job	40s	14.5s	-25.5s	-64%

• Improve maintainability

  • Considerable complexity reduction in GitHub Actions from poetry bootstrapping to managed uv
  • Enforces import formatting - which although had a configuration, was not validated in the pipeline and imports were thus not formatted
  • Automatically update Python linting dependencies through Renovate

• Improve developer experience

  • Standardises across gherkin, messages and expressions

• Removed deprecated poetry APIs before they are removed; and the following warning on builds: The "poetry.dev-dependencies" section is deprecated and will be removed in a future version. Use "poetry.group.dev.dependencies" instead.

🏷️ What kind of change is this?

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

♻️ Anything particular you want feedback on?

• Aligns with Optimise Python tooling infrastructure messages#324 and Enhance Python tooling infrastructure gherkin#439

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.