[RFC] Remove the GitHub Action

Describe the bug

This repo opted into GitHub Actions as an “action” back during the alpha phase.

I don’t think I thought enough about the repercussions, the CI for other takes much longer and is less predictable. I think it’s just a much worse version of npx danger ci and we should probably stop making this repo show up as a GitHub Action.

This also means updating some docs, and I think there are recommendations in the errors which use the action syntax.

[orta]

I also think it’s a bad abstraction in danger-swift too, you can’t share the build phase at all and so the problem is exacerbated over there with danger taking many minutes to be used. I almost unilaterally recommend that people never use the actions IRL.

The biggest advantage is that it can have danger-js etc all set up ahead of time

I don’t think it’s about removing the docker support, that’s tangential - people are free to set stuff up how they like. If they’re using docker, then they are already used to slow builds. Today people think that the actions are the first thing you should use, and that’s a worse experience then just doing Danger with the rest of your project.

[orta]

I’ve hit the button to delist it, existing workflows will still “work” but folks won’t find it in the future