[3.2.x] Fixed #32645 -- Fixed QuerySet.update() crash when ordered by joined fields on MySQL/MariaDB.

Thanks Matt Westcott for the report.

Regression in 779e615e36.
Backport of ca98729055 from main

tests/update/tests.py

@@ -7,7 +7,10 @@ from django.db.models.functions import Abs, Concat, Lower
 from django.test import TestCase
 from django.test.utils import register_lookup
 
-from .models import A, B, Bar, D, DataPoint, Foo, RelatedPoint, UniqueNumber
+from .models import (
+    A, B, Bar, D, DataPoint, Foo, RelatedPoint, UniqueNumber,
+    UniqueNumberChild,
+)
 
 
 class SimpleTest(TestCase):
@@ -249,3 +252,26 @@ class MySQLUpdateOrderByTest(TestCase):
             ).order_by('number_inverse').update(
                 number=F('number') + 1,
             )
+
+    def test_order_by_update_on_parent_unique_constraint(self):
+        # Ordering by inherited fields is omitted because joined fields cannot
+        # be used in the ORDER BY clause.
+        UniqueNumberChild.objects.create(number=3)
+        UniqueNumberChild.objects.create(number=4)
+        with self.assertRaises(IntegrityError):
+            UniqueNumberChild.objects.order_by('number').update(
+                number=F('number') + 1,
+            )
+
+    def test_order_by_update_on_related_field(self):
+        # Ordering by related fields is omitted because joined fields cannot be
+        # used in the ORDER BY clause.
+        data = DataPoint.objects.create(name='d0', value='apple')
+        related = RelatedPoint.objects.create(name='r0', data=data)
+        with self.assertNumQueries(1) as ctx:
+            updated = RelatedPoint.objects.order_by('data__name').update(name='new')
+        sql = ctx.captured_queries[0]['sql']
+        self.assertNotIn('ORDER BY', sql)
+        self.assertEqual(updated, 1)
+        related.refresh_from_db()
+        self.assertEqual(related.name, 'new')