fix(ci): simplify docker-build to use docker:cli container

.forgejo/workflows/lint-and-build.yml

@@ -25,18 +25,15 @@ jobs:
 
   docker-build:
     runs-on: docker
+    container:
+      image: docker:cli
+      volumes:
+        - /var/run/docker.sock:/var/run/docker.sock
     steps:
       - name: Checkout
         uses: actions/checkout@v4
       
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-      
       - name: Build Docker image
-        uses: docker/build-push-action@v5
-        with:
-          context: ./backend
-          push: false
-          tags: normogen-backend:latest
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
+        run: |
+          cd backend
+          docker build -t normogen-backend:latest .