CI: use app token for labeler

.github/workflows/labeler.yml

@@ -12,6 +12,12 @@ jobs:
   label:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/create-github-app-token@v1
+        id: app-token
+        with:
+          app-id: "2729701"
+          private-key: ${{ secrets.GH_APP_PRIVATE_KEY }}
       - uses: actions/labeler@v5
         with:
           configuration-path: .github/labeler.yml
+          repo-token: ${{ steps.app-token.outputs.token }}