* 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`.
This is all work of Marc Weber <marco-oweber@gmx.de>, except for a few nitpicks.
Tested space blowup: IMHO negligible to headers and similar stuff,
e.g. the firefox closure (reported by du) grows from 560 to 579 MB.
Saving space should be handled separately,
e.g. we have the multiple-outputs branch.
