Ability to prevent users from creating Tasks that are not part of a Project

When a user clicks on the New Task button on the MyWork page, this new task does not need to be associated with a Project, and it can accept hours. The problem is that we transfer all of our time data in Workfront to our financial system, and all of the time data needs to be associated with a Project because the Project contains all the metadata that we need. So, we need the ability to prevent users from creating their own tasks that are not associated with any project, so that users don't accidentally log time on these orphan tasks.