Make steps that ignore the outcome or can run in background

Seems like a good addition could be steps that we just dont wait for. A fire and forget lets call it.

Could be implemented on the commands for now as that seems the most obvious use case.

Also it could be nice to have them run on the background. Which means still get the output but dont block other steps from running.

stages:
    default:
      - name: "Run some commands"
        type: {ignore-exit, default, background}
        commands:
          - sleep 20 && echo "done"

Start by tracing how stages execute their command steps and how the YAML type value is handled. Define the behavior for ignore-exit and background, including failure handling, output, and whether later steps continue; done means the example configuration works without blocking as described.