Fix: Run update hooks when finalizing order

When defining an update hook in the order model like this:

```ruby
Spree::Order.class_eval do
  register_update_hook :do_stuff

  def do_stuff
    ...
  end
end
```

and later call `order.save` or `order.finalize`

**Expected** 

`do_stuff` should be called

**Actual**

`do_stuff` is only called during #update, but not #finalize