Fix GitHub Actions security - add explicit permissions

Co-authored-by: AmedeoPelliccia <164860269+AmedeoPelliccia@users.noreply.github.com>

Author: Copilot

.github/workflows/nomenclature-validation.yml

@@ -11,6 +11,9 @@ jobs:
     runs-on: ubuntu-latest
     name: Validate File Nomenclature
 
+    permissions:
+      contents: read
+    
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4