[Bug 2125153] ibus does not support special Arabic compose sequences

https://bugzilla.redhat.com/show_bug.cgi?id=2125153

--- Comment #3 from Mike FABIAN  ---
The same trick works for Gtk3, I was confused for a moment because I happened
to have a ~/.config/gtk-3.0/Compose file and then Gtk3 reads **only** that,
see: https://docs.gtk.org/gtk3/class.IMContextSimple.html

But after I deleted ~/.config/gtk3/Compose, the sequences

$ cat ~/.XCompose
    include "/%L"
    <UFEFB>     :   "لا" # ARABIC LIGATURE LAM WITH ALEF
    <U263A> : "single char compose sequence worked"
    $

worked in

env GTK_IM_MODULE=gtk-im-context-simple gedit

as well.

But it **still** does **not** work in Gtk4, although I made sure that
~/.config/gtk-4.0/Compose did not exist and confirmed that other compose
sequences like

<Multi_key> <m> <o> <u> <s> <e> : "🐭" # U+1F42D MOUSE FACE

defined in ~/.XCompose worked with

env GTK_IM_MODULE=gtk-im-context-simple gnome-text-editor

and

env GTK_IM_MODULE=gtk-im-context-simple gtk4-demo

the compose sequences

<UFEFB>     :   "لا" # ARABIC LIGATURE LAM WITH ALEF
    <U263A> : "single char compose sequence worked"

still did not work with Gtk4.