a11y: Remove keysnooping support
a11y: Remove keysnooping support

As previously announced, key snooping is something that we should not
support in GTK. In particular because AT-SPI made every key press a
synchronous DBUS call / spawned a nested main loop with the key
snoopers. This breaks responsiveness, order of key presses and internal
consistency when the AT decides to remove key events.

jigpu/gtk,ebassi/gtk,jadahl/gtk,davidgumberg/gtk,Adamovskiy/gtk,Adamovskiy/gtk,jigpu/gtk,Lyude/gtk-,Adamovskiy/gtk,ebassi/gtk,Distrotech/gtk2,ahodesuka/gtk,alexlarsson/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jigpu/gtk,chergert/gtk,davidt/gtk,ahodesuka/gtk,ebassi/gtk,Sidnioulz/SandboxGtk,grubersjoe/adwaita,bratsche/gtk-,Lyude/gtk-,chergert/gtk,Sidnioulz/SandboxGtk,chergert/gtk,davidgumberg/gtk,davidt/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,chergert/gtk,bratsche/gtk-,jadahl/gtk,davidt/gtk,Distrotech/gtk2,ebassi/gtk,jadahl/gtk,grubersjoe/adwaita,davidt/gtk,ahodesuka/gtk,davidgumberg/gtk,alexlarsson/gtk,jessevdk/gtk,jadahl/gtk,ahodesuka/gtk,msteinert/gtk,bratsche/gtk-,chergert/gtk,Sidnioulz/SandboxGtk,jessevdk/gtk,alexlarsson/gtk,msteinert/gtk,bratsche/gtk-,davidgumberg/gtk,msteinert/gtk,alexlarsson/gtk,jigpu/gtk,jessevdk/gtk,alexlarsson/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jessevdk/gtk,Adamovskiy/gtk,alexlarsson/gtk,chergert/gtk,jessevdk/gtk,bratsche/gtk-,davidgumberg/gtk,bratsche/gtk-,Distrotech/gtk2,Distrotech/gtk2,davidt/gtk,davidgumberg/gtk,msteinert/gtk,alexlarsson/gtk,ahodesuka/gtk,Distrotech/gtk2,jessevdk/gtk,chergert/gtk,msteinert/gtk,grubersjoe/adwaita,jadahl/gtk,Lyude/gtk-,grubersjoe/adwaita,davidt/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,davidgumberg/gtk,jadahl/gtk,ebassi/gtk,Adamovskiy/gtk,Distrotech/gtk2,ahodesuka/gtk,Lyude/gtk-,chergert/gtk,davidgumberg/gtk,grubersjoe/adwaita,alexlarsson/gtk,Lyude/gtk-,jadahl/gtk,jigpu/gtk,Lyude/gtk-,ebassi/gtk,msteinert/gtk,jadahl/gtk,ahodesuka/gtk,grubersjoe/adwaita,jigpu/gtk,Lyude/gtk-,Sidnioulz/SandboxGtk,jigpu/gtk,Lyude/gtk-,jessevdk/gtk