Since GNOME 44, extension schemas are compiled at install time.
At the time GNOME 46 is released, this will be all supported versions,
so start relying on it and drop the old compatibility
code.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3042>
GSettings schemas are now compiled at install time, so it is no
longer necessary to include the compiled schema in the archive.
However the `gnome-extensions pack` command hasn't been adjusted,
so that it can still be used to produce valid archives for all
supported versions.
To not let that code linger forever, error out when building
a version where GNOME 44 is the oldest supported release.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2639>
When we allow users to choose between different templates, we should
provide some context for each template to facilitate that choice.
Add that metadata in the form of a .desktop file, which allows us to
specify name and description, and is well supported by our translation
infrastructure.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/812
The gnome-extensions tool code is really independent from the rest of the
code base, and could be used either as part of the gnome-shell build or as
stand-alone project (for example for the extension-ci docker image).
We can actually support both cases by moving the code to a subproject.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/877
