Official Air GitHub Actions for formatting

[DavisVaughan]

The Shiny one has a lot of the customization I'd want
https://github.com/rstudio/shiny-workflows/blob/main/format-r-code/action.yaml

• Pinning a version
• Formatting followed by committing if any files were formatted
• Check mode that errors rather than committing
• Default formats . but provide some way to customize the path(s), or maybe a way to customize the working directory

I'm not sure if we want it to be a composite workflow like the Shiny one or if we want to, say, always make it run on ubuntu-latest.

This probably needs to be its own repo so we can use tags to version the workflow

The ruff one is fairly sophisticated, and is not a composite workflow
https://github.com/astral-sh/ruff-action/tree/main

The ruff one even lives in the official marketplace
https://github.com/marketplace/actions/ruff-action