ci: Restrict PR title check job permissions (#3082)

* Restrict job persmisisons

* Move permissions to top-level

Author: nr-ahemsath

.github/workflows/pr_title_checker.yml

@@ -1,16 +1,18 @@
 name: Ensure PR title has a valid prefix
 
 on:
-  pull_request:
-    branches:
-      - main
   pull_request_target:
     types:
       - opened
       - edited
       - synchronize
       - labeled
       - unlabeled
+    branches:
+      - main
+
+permissions:
+  read-all
 
 jobs:
   check: