Enhance Git LFS handling in MKDocs Docker workflow

.gitea/workflows/build-and-push-mkdocs-docker-image.yml

@@ -31,7 +31,15 @@ jobs:
             -   name: Checkout code
                 uses: https://github.com/actions/checkout@v4
                 with:
-                    lfs: true
+                    persist-credentials: 'true' # Optional; should be the default
+
+            -   name: Checkout lfs
+                run: |
+                    git lfs install --local
+                    AUTH=$(git config --local http.${{ github.server_url }}/.extraheader)
+                    git config --local --unset http.${{ github.server_url }}/.extraheader
+                    git config --local http.${{ github.server_url }}/${{ github.repository }}.git/info/lfs/objects/batch.extraheader "$AUTH"
+                    git lfs pull
 
             -   name: Set up Docker Buildx
                 uses: https://github.com/docker/setup-buildx-action@v3