forgejo-runner(host): configure some more labels for more images

Provide the ubuntu labels similar to the images running at Codeberg
using the catthehacker/ubuntu:act-* images.
See:
https://github.com/catthehacker/docker_images
https://codeberg.org/actions/meta

Also provide convenience labels for Alpine and Debian.

resources/chaosknoten/forgejo-runner/forgejo-runner/configuration.yaml.j2

@@ -14,6 +14,15 @@ runner:
   labels:
     # https://forgejo.org/docs/latest/admin/actions/configuration/#choosing-labels
     - docker:docker://docker.io/library/node:lts
+    # Provide ubuntu labels similar to the images running at Codeberg.
+    # https://github.com/catthehacker/docker_images
+    # https://codeberg.org/actions/meta
+    - ubuntu-latest:docker://ghcr.io/catthehacker/ubuntu:act-latest
+    - ubuntu-24.04:docker://ghcr.io/catthehacker/ubuntu:act-24.04
+    # Alpine
+    - alpine:docker://docker.io/library/alpine:latest
+    # Debian
+    - debian:docker://docker.io/library/debian:latest
 
 cache:
   enabled: false