Ignore XkbMapNotify events that don't belong to the core keyboard

This MR fix a problem with VMWare Workstation and Omnissa-Horizon (VDI) with libxkbcommon0 1.12.3-1. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1120988

More details can be found in https://github.com/xkbcommon/libxkbcommon/issues/888

Patch has been cherry picked from https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/293

Signed-off-by: Daniel Schröter d.schroeter@gmx.de