Fix error when make lint in test_type_engine.py

tests/flytekit/unit/core/test_type_engine.py

@@ -3624,12 +3624,6 @@ def test_structured_dataset_mismatch():
     with pytest.raises(TypeTransformerFailedError):
         TypeEngine.to_literal(FlyteContext.current_context(), df, StructuredDataset, TypeEngine.to_literal_type(StructuredDataset))
 
-try:
-    from typing import Union
-    union_type = Union[int, str]
-except TypeError:
-    union_type = int | str  # For Python 3.10+
-
 @pytest.mark.skip(reason="assert_type method not found in TypeEngine")
 def test_assert_type_with_optional():
     engine = TypeEngine()
@@ -3641,7 +3635,7 @@ def test_assert_type_with_optional():
 def test_assert_type_with_union():
     engine = TypeEngine()
     value = "test"
-    expected_type = union_type
+    expected_type = int | str if sys.version_info >= (3, 10) else Union[int, str]
     engine.assert_type(expected_type, value)
 
 @pytest.mark.skip(reason="_fix_dataclass_int method not found in TypeEngine")