[4.1.x] Fixed #33984 -- Reverted "Fixed #32980 -- Made models cache related managers."

This reverts 4f8c7fd9d91b35e2c2922de4bb50c8c8066cbbc6 and adds
two regression tests:
- test_related_manager_refresh(), and
- test_create_copy_with_m2m().

Thanks joeli for the report.
Backport of 5e0aa362d91d000984995ce374c2d7547d8d107f from main

2 files changed, 6 insertions, 1 deletions

diff --git a/docs/releases/4.1.2.txt b/docs/releases/4.1.2.txt
index d607c34c92..498c645920 100644
--- a/docs/releases/4.1.2.txt
+++ b/docs/releases/4.1.2.txt
@@ -43,3 +43,7 @@ Bugfixes
 * Fixed a regression in Django 4.1 that caused a crash for :class:`View`
   subclasses with asynchronous handlers when handling non-allowed HTTP methods
   (:ticket:`34062`).
+
+* Reverted caching related managers for ``ForeignKey``, ``ManyToManyField``,
+  and ``GenericRelation`` that caused the incorrect refreshing of related
+  objects (:ticket:`33984`).
diff --git a/docs/releases/4.1.txt b/docs/releases/4.1.txt
index 11268df298..08fb7c2abc 100644
--- a/docs/releases/4.1.txt
+++ b/docs/releases/4.1.txt
@@ -530,7 +530,8 @@ Miscellaneous
 * Related managers for :class:`~django.db.models.ForeignKey`,
   :class:`~django.db.models.ManyToManyField`, and
   :class:`~django.contrib.contenttypes.fields.GenericRelation` are now cached
-  on the :class:`~django.db.models.Model` instance to which they belong.
+  on the :class:`~django.db.models.Model` instance to which they belong. *This
+  change was reverted in Django 4.1.2.*
 
 * The Django test runner now returns a non-zero error code for unexpected
   successes from tests marked with :py:func:`unittest.expectedFailure`.