fix: correct function name in test_fix_verification.py

- Changed register_callback to register_display_callback
- Ensures test runs correctly and validates the fix

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Co-authored-by: Mervin Praison <MervinPraison@users.noreply.github.com>

Author: github-actions[bot]

test_fix_verification.py

@@ -11,8 +11,8 @@ def test_callback(**kwargs):
     # because the callback functions would try to access task_name but it wasn't passed
 
 # Register the callback
-from praisonaiagents.main import register_callback
-register_callback('interaction', test_callback)
+from praisonaiagents.main import register_display_callback
+register_display_callback('interaction', test_callback)
 
 # Example tool
 def simple_tool():