Refs #29708 -- Removed PickleSerializer per deprecation timeline.

tests/defer_regress/tests.py

@@ -1,11 +1,9 @@
 from operator import attrgetter
 
 from django.contrib.contenttypes.models import ContentType
-from django.contrib.sessions.backends.db import SessionStore
 from django.db import models
 from django.db.models import Count
-from django.test import TestCase, ignore_warnings, override_settings
-from django.utils.deprecation import RemovedInDjango50Warning
+from django.test import TestCase
 
 from .models import (
     Base,
@@ -106,29 +104,6 @@ class DeferRegressionTest(TestCase):
             list(SimpleItem.objects.annotate(Count("feature")).only("name")), list
         )
 
-    @ignore_warnings(category=RemovedInDjango50Warning)
-    @override_settings(
-        SESSION_SERIALIZER="django.contrib.sessions.serializers.PickleSerializer"
-    )
-    def test_ticket_12163(self):
-        # Test for #12163 - Pickling error saving session with unsaved model
-        # instances.
-        SESSION_KEY = "2b1189a188b44ad18c35e1baac6ceead"
-
-        item = Item()
-        item._deferred = False
-        s = SessionStore(SESSION_KEY)
-        s.clear()
-        s["item"] = item
-        s.save(must_create=True)
-
-        s = SessionStore(SESSION_KEY)
-        s.modified = True
-        s.save()
-
-        i2 = s["item"]
-        self.assertFalse(i2._deferred)
-
     def test_ticket_16409(self):
         # Regression for #16409 - make sure defer() and only() work with annotate()
         self.assertIsInstance(