Before this commit, when changing the website field in a record form view,
the is_published field would be force to false, ending unpublishing the record
if it was published.
That behavior was coming from the fact that is_published field is missing from
the form view. Thus, onchange on website is triggering a recompute server side
without is_published as the JS framework is not sending the field.
The ORM is then fallbacking on default Boolean value (False) for is_published
when sending back the onchange result.
This would only appear on object with 'website.published.multi.mixin' and with
website_id in the form view.
Replacing website_published by is_published will fix the behavior and has more
sense has website_published is the 'is_published' state in a website context.
In the backend, we are not in a website context.
task-1919689