fix: Create demo branch if it doesn't exist

Author: ChenZiHong-Gavin

.github/workflows/sync-demo.yml

@@ -17,6 +17,16 @@ jobs:
         ref: main
         token: ${{ secrets.GITHUB_TOKEN }}
 
+    - name: Create demo branch if it doesn't exist
+      run: |
+        if ! git ls-remote --heads origin demo | grep -q demo; then
+        echo "Creating demo branch..."
+        git checkout -b demo
+        git push origin demo
+        else
+        echo "Demo branch already exists"
+        fi
+
     - name: Checkout demo branch
       uses: actions/checkout@v4
       with: