Use only ruff for Python linting and formatting

[taldcroft]

Description

This updates the template files to match what was successfully used in sot/kadi#268.

One slight departure from the "ruff-only" theme is moving the pyright configuration into its dedicated JSON file. There is a question about whether it is better to glop all tool config into one pyproject.toml file or use separate config files where possible. For this application where we want to apply the same files to many projects, I believe that having separate config files works better. If we want to apply a mass update then it is just a matter of copying a new file (e.g. ruff.toml) instead of editing a section in pyproject.toml.

Testing

The files were successfully used in sot/kadi#268, including inadvertent lint/format mistakes that ended up triggering pre-commit and GitHub action failures (both format and lint for each case).

I also confirmed that the new pyrightconfig.json file successfully forces pyright in VS code to ignore notebooks. Without that file I see spurious pyright errors in the notebook (e.g. "Unresolved import" for cxotime which is clearly wrong).