Why do you need to have node installed to run setup-node?

.forgejo/runner/Dockerfile

@@ -0,0 +1,11 @@
+FROM barichello/godot-ci:4.5.1
+
+# Install Node 24 from Alpine
+RUN apt-get update && apt-get install -y curl \
+    && curl -fsSL https://deb.nodesource.com/setup_24.x | bash - \
+    && apt-get install -y nodejs \
+    && rm -rf /var/lib/apt/lists/*
+
+# Verify installations
+RUN node --version
+

.forgejo/workflows/build.yml

@@ -8,16 +8,20 @@ on:
       - "v*.*.*"   # only match version tags like v1.0.0
 
 jobs:
+  prepare:
+    name: Build & push runner image
+    runs-on: docker-cli-node24   # the label of your runner
+    steps:
+      - name: Build & push runner image
+        run: |
+          docker build --network=host -t ${{ vars.REGISTRY_URL }}/asteroids/runner:latest -f .forgejo/runner/Dockerfile .
+          docker push ${{ vars.REGISTRY_URL }}/asteroids/runner:latest
+
   export:
     runs-on: docker-cli-node24
     container:
-      image: barichello/godot-ci:4.5.1  # contains Godot headless + export templates
+      image: ${{ vars.REGISTRY_URL }}/asteroids/runner:latest
     steps:
-      - name: Setup Node
-        uses: actions/setup-node@v6
-        with: 
-          node-version: 24
-          
       - name: Checkout
         uses: actions/checkout@v5