Split extension app out of gnome.gnome-shell

[KCynk]

Describe the bug

gnome.gnome-shell-extensions can't be removed

Steps To Reproduce

Steps to reproduce the behavior:

1. Exclude package
2. Rebuild
3. Reboot
4. Package still exists

Expected behavior

gnome.gnome-shell-extensions should be removed

https://github.com/NixOS/nixpkgs/blob/nixos-23.11/nixos/modules/services/x11/desktop-managers/gnome.nix#L451 https://github.com/NixOS/nixpkgs/blob/nixos-23.11/nixos/modules/services/x11/desktop-managers/gnome.nix#L381

Additional context

In situation when package can't be removed because is required by gnome-shell maybe it will be better replace gnome.gnome-shell-extensions by gnome-extension-manager in new gnome release of NixOS? As is the case with openSuSe MicroOS and Fedora Silverblue spins ( Universal Blue ).

Notify maintainers

@jtojnar @amaxine @dasj19 @hedning @bobby285271

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

[kamilcynk@nixos:~]$  nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 6.6.22, NixOS, 24.05 (Uakari), 24.05pre598982.b06025f1533a`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.18.2`
 - channels(root): `"nixos"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

[jtojnar]

That is part of gnome.gnome-shell itself, not gnome.gnome-shell-extensions.

It might be possible to build it separately, since it is a Meson subproject. Maybe someone can tackle that after we are done with GNOME 46.

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/excluding-gnome-extensions-not-working-removing/50048/5