Use Union type to pass make lint check

Use Union type to pass make lint check:

tests/integration_tests/vectorstores/test_oraclevs.py:1891: error: X | Y syntax for unions requires Python 3.10  [syntax]
tests/integration_tests/vectorstores/test_oraclevs.py:2028: error: X | Y syntax for unions requires Python 3.10  [syntax]
Found 2 errors in 1 file (checked 22 source files)
make: *** [Makefile:33: lint] Error 1

Author: paxiaatucsdedu

libs/oracledb/tests/integration_tests/vectorstores/test_oraclevs.py

@@ -12,6 +12,7 @@
 import logging
 import sys
 import threading
+from typing import Union
 
 import oracledb
 import pytest
@@ -1888,7 +1889,7 @@ def test_db_filter_test() -> None:
         for filtered_function in FILTERED_FUNCTIONS:
             method = getattr(vs, filtered_function)
 
-            query_emb: list[float] | str = query
+            query_emb: Union[list[float], str] = query
             if "_by_vector" in filtered_function:
                 query_emb = vs.embedding_function.embed_query(query)  # type: ignore[union-attr]
 
@@ -2025,7 +2026,7 @@ async def test_db_filter_test_async() -> None:
         for filtered_function in FILTERED_FUNCTIONS:
             method = getattr(vs, "a" + filtered_function)
 
-            query_emb: list[float] | str = query
+            query_emb: Union[list[float], str] = query
             if "_by_vector" in filtered_function:
                 query_emb = vs.embedding_function.embed_query(query)  # type: ignore[union-attr]