Update test_serialization.py to add copyright.

Author: qiuosier

tests/unitary/with_extras/langchain/test_serialization.py

@@ -1,3 +1,10 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*--
+
+# Copyright (c) 2023 Oracle and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+
+
 import os
 from unittest import TestCase, mock, SkipTest