Servicing the widgetUpdateRequest key rewrote it synchronously inside the
change handler of the property bound to it. Qt dropped the re-entrant binding
update as a loop, so the applet kept seeing "check" or "install" and started
a new updater run each time the previous one finished.

Co-authored-by: Lucenx9 <185146821+Lucenx9@users.noreply.github.com>