How do I alter this select list programmatically in my module?
Permissions won't work here since all the roles can use the 'Request publish' transition, but the roles that can also use the 'Published' transition don't need to see 'Request publish'. I think the easiest way to make this change is to remove 'Request publish' from the dropdown list.
I'm working with hook_field_widget_form_alter()
The code that I'm trying to override is from formElement() in ModerationStateWidget.php.