MDL-32630 workshop_calendar_update() does not check for calendar permissions
As discussed in MDL-32631, calendar_event::update() should not do
capability checks at all. Until that issue is fixed, we just explicitly
declare that no capability checks should be done.
The function workshop_calendar_update() is executed when adding or
updating a workshop instance (where permissions to modify the instance
were already checked and are sufficient) and in the upgrade code (where
no check should be performed anyway).