Update tests/client/test_client.py

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

Author: kthota-g

tests/client/test_client.py

@@ -1285,5 +1285,7 @@ async def test_send_message_client_timeout(
 
         request = SendMessageRequest(id=123, params=params)
 
-        with pytest.raises(A2AClientTimeoutError):
+        with pytest.raises(A2AClientTimeoutError) as exc_info:
             await client.send_message(request=request)
+
+        assert 'Request timed out' in str(exc_info.value)