Potential fix for code scanning alert no. 3: Workflow does not contain permissions (#57)

Author: friedrichg

.github/workflows/validate_pr.yml

@@ -4,6 +4,8 @@ on:
     paths-ignore:
       - "docs/**"
       - "*.md"
+permissions:
+  contents: read
 jobs:
   lint:
     name: Lint