Allow for tours to be shown only once

This extension is being deprecated, see 🌱 [Meta] Tasks to deprecate Tour module Fixed . It will be removed from core and moved to a contrib project, 📌 [11.x] [Meta] Tasks to remove Tour Postponed .

This is now Postponed. The status is set according to two policies. The Remove a core extension and move it to a contributed project → and the Extensions approved for removal → policies.

In 🐛 Show (disabled) Tour and Edit buttons on pages with no tour/edit available Fixed we eventually are going to always have the Tour icon shown. Currently we don't have the back functionality either. So think the ability to rerun tours make sense and without it will make tours less useful. This functionality could probably be a separate tour contrib module.