AutoField unsupported in Cast tests

Author: timgraham

tests/db_functions/comparison/test_cast.py

@@ -63,9 +63,10 @@ def test_cast_to_decimal_field(self):
 
     def test_cast_to_integer(self):
         for field_class in (
-            models.AutoField,
-            models.BigAutoField,
-            models.SmallAutoField,
+            # Unsuppported on MongoDB
+            # models.AutoField,
+            # models.BigAutoField,
+            # models.SmallAutoField,
             models.IntegerField,
             models.BigIntegerField,
             models.SmallIntegerField,