Fix GitHub Actions and Python upgrade to >=3.10

- Fix GitHub Actions by setting correct branch in `.github/workflows/test.yaml` from master to main.
- Added `.pre-commit-config.yaml` and prek to automate checks easily
- Bumped minimum Python version to 3.10
- Added support for Python 3.14, 3.15, and their free-threaded variants
- Added various dependency_groups to pyproject.toml
- Modify tests.yaml to use `uv run` instead of `uvx`
- Fix readme-renderer