Update commit-signing (#3027)

Author: ChiaAutomation

.github/workflows/check-commit-signing.yml

@@ -10,6 +10,9 @@ on:
     branches:
       - "**"
 
+permissions:
+  contents: read
+
 concurrency:
   group: ${{ github.event_name == 'pull_request' && format('{0}-{1}', github.workflow_ref, github.event.pull_request.number) || github.run_id }}
   cancel-in-progress: true