Another minor unit test tweak

Use monkeypatch to manipulate system path -- this ensures that the
change will also be undone after the test runs.

Author: pont-us

test/test_wrapper.py

@@ -6,7 +6,8 @@
 @patch("sys.argv", ["wrapper.py", "--verbose"])
 def test_wrapper(tmp_path, monkeypatch):
     import xcengine
-    sys.path += xcengine.__path__
+    for path in xcengine.__path__:
+        monkeypatch.syspath_prepend(path)
     user_code_path = (tmp_path / "user_code.py")
     user_code_path.touch()
     os.environ["XC_USER_CODE_PATH"] = str(user_code_path)