added back workflow level permissions config

revert of commit 3760d1a

Author: hhund

.github/workflows/build.yml

@@ -13,6 +13,8 @@ on:
   schedule:
     - cron: '11 15 * * 0' # Sundays, 15:11
 
+permissions: {}
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
   cancel-in-progress: true