Refs #34986 -- Avoided implementation-specific unpickleable types.

The implementation of some core types differ between CPython and PyPy
and this may affect the way that pickling works such that errors are
raised in differing locations in the interpreter or not at all.

Use our own custom non-pickleable type instead to avoid these quirks.

tests/queries/tests.py

@@ -3,7 +3,6 @@ import pickle
 import sys
 import unittest
 from operator import attrgetter
-from threading import Lock
 
 from django.core.exceptions import EmptyResultSet, FieldError, FullResultSet
 from django.db import DEFAULT_DB_ALIAS, connection
@@ -113,6 +112,11 @@ from .models import (
 )
 
 
+class UnpickleableError(Exception):
+    def __reduce__(self):
+        raise type(self)("Cannot pickle.")
+
+
 class Queries1Tests(TestCase):
     @classmethod
     def setUpTestData(cls):
@@ -2571,8 +2575,8 @@ class CloneTests(TestCase):
         # Evaluate the Note queryset, populating the query cache
         list(n_list)
         # Make one of cached results unpickable.
-        n_list._result_cache[0].lock = Lock()
-        with self.assertRaises(TypeError):
+        n_list._result_cache[0].error = UnpickleableError()
+        with self.assertRaises(UnpickleableError):
             pickle.dumps(n_list)
         # Use the note queryset in a query, and evaluate
         # that query in a way that involves cloning.