add sync fork workflow

.github/workflows/sync.yml

@@ -0,0 +1,26 @@
+name: Sync fork
+  
+permissions:
+  contents: write
+
+on:
+  schedule:
+    - cron: "0 0 * * *"
+  workflow_dispatch:
+
+jobs:
+  sync:
+    name: Sync fork
+    runs-on: ubuntu-latest
+    if: ${{ github.event.repository.fork }}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Sync fork
+        run: gh repo sync ${{ github.repository }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+
+      - uses: gautamkrishnar/keepalive-workflow@v1