wayland: Guard wayland object destructors
Kidletime is a singleton and the client API works by supplying ints to add or remove timeouts. When not all timeouts are removed before program exits, trying to destroy the wayland objects will crash since the lifetime of the wayland connection is tied to the QGuiApplication. BUG:465801 FIXED-IN:5.104
(cherry picked from commit 53779a8d)