Support async agent and model callbacks

PiperOrigin-RevId: 755542756

tests/integration/test_evalute_agent_in_fixture.py

@@ -19,6 +19,7 @@ import os
 from google.adk.evaluation import AgentEvaluator
 import pytest
 
+
 def agent_eval_artifacts_in_fixture():
   """Get all agents from fixture folder."""
   agent_eval_artifacts = []