fix: does_not_raise

tests/test_parser.py

@@ -1,17 +1,13 @@
 """Unit tests for pytiled_parser"""
 
 import xml.etree.ElementTree as etree
-from contextlib import contextmanager
+from contextlib import ExitStack as does_not_raise
 
 import pytest
+
 from pytiled_parser import objects, utilities, xml_parser
 
 
-@contextmanager
-def does_not_raise():
-    yield
-
-
 def _get_root_element(xml: str) -> etree.Element:
     """Get root element of string of XML.