Create Docker image for Runner in arm64
With #4870 we started distributing Runner binaries for arm64, so that they can run their Runner process on an arm64 machine. However, we don't provide a Docker image so that the user can runner the Runner process inside of a Docker container as specified in https://docs.gitlab.com/runner/install/docker.html.
Provide an arm64 Docker image that that will have GitLab Runner so that they can start running GitLab Runner manager inside of a Docker container. As pointed out in !725 (comment 226637168) we have a problem with this because we use
dumb-init to have
gitlab-runner process start on PID 1. There an open issue upstream that we need to investigate, it was also suggested that we might want to migrate to
tini which might be a solution.