fix: printing job admin auto complete for product field

printing/tests.py

@@ -69,3 +69,17 @@ class PrintingJobAdminSearchTestCase(TestCase):
 
         self.assertFalse(may_have_duplicates)
         self.assertEqual(list(queryset), [self.job])
+
+    def test_printing_job_admin_uses_autocomplete_for_large_relations(self):
+        model_admin = printing_admin.PrintingJobAdmin(printing_models.PrintingJob, self.site)
+
+        self.assertEqual(
+            model_admin.autocomplete_fields,
+            (
+                'merchant',
+                'printing_order',
+                'product',
+                'business_object',
+                'created_by',
+            ),
+        )