Ignore ResourceWarning in test.

This is expected to prevent a spurious test failure under PyPy.

Refs #1483.

tests/legacy/utils.py

@@ -2,6 +2,7 @@
 import contextlib
 import functools
 import logging
+import sys
 import unittest
 
 
@@ -76,8 +77,19 @@ def assertDeprecationWarnings(self, recorded_warnings, expected_warnings):
         Check recorded deprecation warnings match a list of expected messages.
 
         """
+        # Work around https://github.com/python/cpython/issues/90476.
+        if sys.version_info[:2] < (3, 11):  # pragma: no cover
+            recorded_warnings = [
+                recorded
+                for recorded in recorded_warnings
+                if not (
+                    type(recorded.message) is ResourceWarning
+                    and str(recorded.message).startswith("unclosed transport")
+                )
+            ]
+
         for recorded in recorded_warnings:
-            self.assertEqual(type(recorded.message), DeprecationWarning)
+            self.assertIs(type(recorded.message), DeprecationWarning)
         self.assertEqual(
             {str(recorded.message) for recorded in recorded_warnings},
             set(expected_warnings),