CI: clone from the forge's public address

The forge VM's runner reports http://localhost:3000 as the server URL,
which the job container can't reach.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.forgejo/workflows/deploy.yml

@@ -22,10 +22,12 @@ jobs:
     steps:
       - name: Tools
         run: dnf install -y --quiet git-core jq curl
-      # A plain clone: the container has no Node for actions/checkout.
+      # A plain clone: the container has no Node for actions/checkout. The
+      # forge's public address: this runner is told localhost:3000, which
+      # the container can't reach.
       - name: Checkout
         run: |
-          git clone -q "https://ci:${{ github.token }}@${GITHUB_SERVER_URL#https://}/${{ github.repository }}.git" .
+          git clone -q "https://ci:${{ github.token }}@forge.quinefoundation.com/${{ github.repository }}.git" .
           git checkout -q "${{ github.sha }}"
       - uses: https://forge.quinefoundation.com/quine-global/site-image@v1
         with: