The runners come with a number of pre-cached Docker images, none of which is of use to us. We should clean them up to free up some more disk space.
Comment From: wilkinsona
While not listed in the runner documentation, I think this may have broken our ability to use actions that are packaged as a Docker image:
Unable to find image '871515:68fcdc6e598b460fb64f8d27d0c4e522' locally
docker: Error response from daemon: pull access denied for 871515, repository does not exist or may require 'docker login': denied: requested access to the resource is denied.
See 'docker run --help'.
This was when trying to build and run spring-io/artifactory-deploy-action@26bbe925a75f4f863e1e529e85be2d0093cac116. If this failure proves not to be a one-off, we'll have to revert this change.