Update tests/server/routes/test_agent_card_route.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: guglielmo-san

tests/server/routes/test_agent_card_route.py

@@ -20,7 +20,7 @@ def mock_agent_card():
 def test_app(mock_agent_card):
     app = Starlette()
     card_route = AgentCardRoutes(mock_agent_card)
-    app.routes.append(card_route.route)
+    app.routes.append(card_route.routes[0])
     return app