[3.14] gh-144984: Skip test under tracerefs (GH-146218) (GH-146384)

(cherry picked from commit 119fce7)

Co-authored-by: Petr Viktorin <encukou@gmail.com>

Author: miss-islington

Lib/test/test_pyexpat.py

@@ -842,6 +842,8 @@ 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