Final removal of old course dashboards
Course dashboard functionality was replaced by the course overview page in a user interface upgrade in 2021. So that teachers would have time to move their content to resources, we have kept the old dashboards available in read-only mode from the course links, together with a warning that they will be removed permanently by the end of 2021. For various reasons, the removal was delayed, but in this release they are now removed from the link collection.