Shallow copying of `django.utils.functional.LazyObject` or its subclasses has
been broken in a couple of different ways in the past, most recently due to
35355a4.
Pickling a `SimpleLazyObject` wrapping a model did not work correctly; in
particular it did not add the `_django_version` attribute added in 42736ac8.
Now it will handle this and other custom `__reduce__` methods correctly.