Potential fix for code scanning alert no. 3: Workflow does not contain permissions (#214)

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: jakubno

.github/workflows/validate-renovate-config.yaml

@@ -8,6 +8,8 @@ on:
 jobs:
   validate-renovate-config:
     runs-on: ubuntu-24.04
+    permissions:
+      contents: read
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6