Ability to skip editable install

[peterfpeterson]

In our normal workflow, we perform editable installs of the package being edited via configuration in our pyproject.toml. This makes other parts of our CI unstable. However, pixi added the ability to skip some packages during install in prefix-dev/pixi#3092. To take advantage of this, we now have a 3 step process for setting up the environment in CI:

1. prefix-dev/setup-pixi with runinstall: false
2. pixi install --frozen --skip ${env.PKG_NAME}
3. pixi run pip install --no-deps -e .

Ideally, I'd like these three steps as configurable through your tool. However, if I could just have a skip-package option (suggested name, but you can pick) and have to do the pip install ... as a follow-on that would still be helpful. I would like this so the full pixi environment could be cached rather than just the tool being installed.

[pavelzw]

i'm wondering whether we should also include --skip-with-deps while we're at it.
we could probably do something like this:

- uses: prefix-dev/setup-pixi@...
  with:
    skip: my-package
    skip-with-deps: pytorch