ci: revert to node runner (ubuntu-latest gave no benefit)

Socket-not-mounted is a runner-config issue, independent of job image.

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

.forgejo/workflows/deploy.yml

@@ -8,10 +8,9 @@ on:
 
 jobs:
   deploy:
-    # `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
+    # `node` => node:22-bookworm (small, fast). We install the docker CLI below.
+    # Requires the runner to mount /var/run/docker.sock into jobs (see repo docs).
+    runs-on: node
     steps:
       - name: Checkout
         uses: actions/checkout@v4