We intend to make all GTK apps depend on the desktop schemas. Since
the schemas depend on gnome-backgrounds to determine the default
wallpaper path, it would increase the closure size significantly
for smaller apps.
We could split out the org.gnome.desktop.background and screensaver
schemas but that would make the packaging unnecessarily complicated.
Instead we remove the backgrounds dependency since they are not used
(outside of GNOME) or they will be replaced by a different set by
the NixOS module. There will be no background when running GNOME
manually but that can be easily fixed.
* gnome3: only maintain single GNOME 3 package set
GNOME 3 was split into 3.10 and 3.12 in #2694. Unfortunately, we barely have the resources
to update a single version of GNOME. Maintaining multiple versions just does not make sense.
Additionally, it makes viewing history using most Git tools bothersome.
This commit renames `pkgs/desktops/gnome-3/3.24` to `pkgs/desktops/gnome-3`, removes
the config variable for choosing packageset (`environment.gnome3.packageSet`), updates
the hint in maintainer script, and removes the `gnome3_24` derivation from `all-packages.nix`.
Closes: #29329
* maintainers/scripts/gnome: Use fixed GNOME 3 directory
Since we now allow only a single GNOME 3 package set, specifying
the working directory is not necessary.
This commit sets the directory to `pkgs/desktops/gnome-3`.
