ci(deps)!: Drop Python 3.9 support, add 3.14, configure updates

[emyller]

Python 3.9 is end-of-life but was still listed as supported. This drops it, adds 3.14, and refreshes the lockfiles to match.

It also declares the supported Python range to Renovate. With normal updates already security-only (#333), this stops a security bump from targeting a release that needs a newer Python than we support.

Changes

• Drop Python 3.9 (end-of-life).
• Add Python 3.14.
• Refresh locked dependencies for the 3.10–3.14 range.
• Constrain Renovate updates to releases compatible with every supported Python.

Closes #332

Review effort: 2/5

[github-actions]

File	Coverage		Missing
All files	100%	✅

Minimum allowed coverage is 100%

Generated by 🐒 cobertura-action against 648474e

[gemini-code-assist]

Code Review

This pull request drops support for Python 3.9, raising the minimum required Python version to 3.10. This change is reflected across the repository, including updating the Renovate configuration, regenerating the development and production requirements files using uv targeting Python 3.10, and updating setup.py with the new python_requires constraint and classifiers. I have no feedback to provide.

[codspeed-hq]

Merging this PR will not alter performance

✅ 1 untouched benchmark

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_{Comparing fix/much-too-renovation (648474e) with main (b8e4a8e)}

[emyller]

@matthewelwell Should this trigger a major release?

[matthewelwell]

@matthewelwell Should this trigger a major release?

Good call. Yes, probably.