The Config module is shared between the main process, D-Bus
services and tests, which previously prevented it from being
ported to ESM.
The previous commit removed the last outstanding blocker, so
we can now port the last remaining module.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2880>
The module is shared between the various D-Bus services and the
main gnome-shell process, so it was originally left out to allow
porting different bits at their own speed.
Now that everything has been ported to ESM, there is no reason
to not move that particular module as well.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2868>