fix github workflow

.github/workflows/docker-build-and-push.yaml

@@ -24,9 +24,10 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        run: |
-        with:
+          git clone --depth 1 --branch ${GITHUB_REF_NAME} \
-          github-server-url: https://chef.heaplab.deib.polimi.it/git
+            https://chef.heaplab.deib.polimi.it/git/${GITHUB_REPOSITORY}.git \
+            ${GITHUB_WORKSPACE}
 
       - name: Build Docker image
         run: |