menus.ui: Remove Quit entry from Primary Menu

As per the HIG, Quit is not present in Primary Menus, and is
made redundant or confusing with the presence of the close button.
3 jobs for christopherdavis/remove-quit-from-menu in 35 minutes and 8 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #178239
flatpak

00:34:26

 
  Review
passed #178240
review

00:00:42

manual #178241
allowed to fail manual
stop_review