From https://github.com/ibus/ibus/issues/2331#issuecomment-927110685
"There are two modes to communicate between IBus and GTK applications."
- GTK_IM_MODULE=wayland (composer mode - GNOME Wayland default) and
GTK_IM_MODULE=ibus (no composer mode).

Note that "wayland" im module is another incarnation of ibus.
The only thing that was broken for sure is "xim" so override only it
under Gnome on X11 to prevent making SWT(and as a result Eclipse) use
non-default IM modules and thus exposing different behaviour than other
apps.