gh-144984: Skip test under tracerefs

Author: encukou

Lib/test/test_pyexpat.py

@@ -854,6 +854,8 @@ class ExternalEntityParserCreateErrorTest(unittest.TestCase):
     def setUpClass(cls):
         cls.testcapi = import_helper.import_module('_testcapi')
 
+    @unittest.skipIf(support.Py_TRACE_REFS,
+                     'Py_TRACE_REFS conflicts with testcapi.set_nomemory')
     def test_error_path_no_crash(self):
         # When an allocation inside ExternalEntityParserCreate fails,
         # the partially-initialized subparser is deallocated.  This