Revert "Fix issue triage agent: remove lockdown mode"

This reverts commit cf44774.

Author: codebytes

.github/workflows/issue-triage-agent.lock.yml

@@ -8,6 +8,8 @@ permissions:
   issues: read
 tools:
   github:
+    # For now we are enabling lockdown mode for this workflow since it processes issues from the public repo and we want to ensure it only processes trusted input from maintainers.
+    lockdown: true
     toolsets: [issues, labels]
 safe-outputs:
   add-labels: