Add pre-commit support for micropython-lib.

[jimmo]

1. Simplify codeformat.py back to be the same as the main repo version, but without .c/.h support. (It's pretty much just a wrapper around black now)
2. Add pre-commit support (same as main repo).
3. Split the ruff action into its own CI action (same as main repo).

This work was funded through GitHub Sponsors.

[jimmo]

In separate PRs, there are two follow-ups:

• Add checking of the git commit messages. In the main repo we use our own tool (tools/verifygitlog.py) but I don't really want to duplicate that here, and I have a proof-of-concept use the standard gitlint tool that works nicely with pre-commit.
• Same as the main, repo, add codespell checks too.

[dpgeorge]

This looks good, thanks.

I also agree about the follow-up actions.