Potential fix for code scanning alert no. 667: Workflow does not contain permissions

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

Author: vinod0m

.github/workflows/metrics.yml

@@ -1,6 +1,8 @@
 # GitHub Metrics
 # This workflow generates a metrics SVG and commits it to the repository
 name: Metrics Embed
+permissions:
+  contents: write
 
 on:
   schedule: [{cron: "0 0 * * 0"}] # every week