We don't want the "Activities" button in GNOME Classic, but the current
way of handling it is confusing:
- the button is hidden, but the corresponding hot corner
sometimes works (when the application menu isn't open)
- the button is effectively moved inside the menu, although
it's clearly not an app or category
- the apps-menu can be used independent from classic mode, in
which case removing the "Activities" button may not be wanted
Address those points by removing any handling of the activities button
from the apps-menu extension. We will remove it again from the classic
session via a session mode tweak.
https://gitlab.gnome.org/GNOME/gnome-shell-extensions/merge_requests/69
6105eecff2