Potential fix for code scanning alert no. 11: Workflow does not contain permissions (#13614)

Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>
Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

.github/workflows/ci-testing.yml

@@ -4,6 +4,9 @@
 
 name: YOLOv5 CI
 
+permissions:
+  contents: read
+
 on:
   push:
     branches: [master]