Fix permissions for check-run action (#300)

Author: mandreko-bitwarden

.github/workflows/scan.yml

@@ -16,10 +16,14 @@ on:
     branches:
       - "main"
 
+permissions: {}
+
 jobs:
   check-run:
     name: Check PR run
     uses: bitwarden/gh-actions/.github/workflows/check-run.yml@main
+    permissions:
+      contents: read
 
   sast:
     name: SAST scan