Update keep-alive.yml

.github/workflows/keep-alive.yml

@@ -3,10 +3,13 @@ on:
   schedule:
     - cron: "0 0 * * *"
   workflow_dispatch:
+permissions:
+  contents: write
 jobs:
   keep-alive:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - run: git checkout -b keep-alive
+        with:
+          ref: 'keep-alive'
       - uses: gautamkrishnar/keepalive-workflow@v1