ci: update action permissions

Author: steveoh

.github/workflows/pull_request.yml

@@ -6,6 +6,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+
 jobs:
   test-check:
     name: Lint and check types