[orca-list] Don't upgrade to GNOME 3.30 or Gtk+ 3.23 for now

[Joanmarie Diggs <jdiggs igalia com>]

Hey all.

I suspect that a couple of recently-reported problems in GNOME 3.30 are
due to a change made to Gtk+ which, as a side effect, caused us to stop
getting much-needed window-related events. Orca uses those now-missing
events to keep track of what window you're in.

Reliably and performantly hacking around this issue in Orca might prove
challenging. Plus bugs have been open by Samuel against gnome-shell and,
MATE to resolve this issue where it should be resolved. So, for now, as
I stated in the subject, don't upgrade to GNOME 3.30. And don't upgrade
Gtk+ to 3.23, where the change in question can be found.

Sorry for the inconvenience!
--joanie