ci: try ubuntu-latest runner (bundles docker CLI)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.forgejo/workflows/deploy.yml

@@ -8,9 +8,10 @@ on:
 
 jobs:
   deploy:
-    # `docker` runner => node:22-bookworm image WITH the Docker socket available,
-    # so `docker build` / `docker run` control the host's Docker daemon.
-    runs-on: docker
+    # `ubuntu-latest` => catthehacker/ubuntu:act-22.04, which bundles the docker
+    # CLI. NOTE: it still needs the runner to mount /var/run/docker.sock for the
+    # daemon to be reachable — the image alone doesn't provide that.
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4