Update developer instructions for `prek` and autofix.ci

[redeboer]

Update docs/develop.md to match the developer setup in ComPWA/policy#694 and the CI changes in ComPWA/actions#177. The page currently recommends pre-commit and pre-commit-uv, documents the old hook commands, and points contributors to pre-commit.ci.

• Replace the quick-start installation with uv tool install prek and prek install --prepare-hooks; remove pre-commit-uv and explain how existing contributors replace their installed Git hooks, following the implemented policy migrate behavior.
• Update the “Pre-commit” section and formatting/notebook references for prek, preserving or updating MyST anchors and cross-references. Document prek run --all-files and clarify that .pre-commit-config.yaml and hook definitions remain in use.
• Align the checks and dependency-update guidance with poe style / pixi run style using prek and the _upgrade-prek task (prek autoupdate -j8). Mention .prekignore where nested hook configurations, such as test fixtures, must be excluded from workspace discovery.
• Replace pre-commit.ci guidance with the implemented GitHub Actions/autofix.ci workflow, explaining how contributors receive automatic fixes, including fork PRs, and any relevant service limitations.
• Verify commands against the completed upstream migrations and check the documentation build and affected links.