nixos/gnome: Install GNOME Software using module

gnome-software now uses systemd instead of autostart so we need to add it to `systemd.packages`:
0880577507

nixos/modules/services/desktop-managers/gnome.nix

@@ -444,38 +444,31 @@ in
 
     # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/gnome-48/elements/core/meta-gnome-core-apps.bst
     (lib.mkIf serviceCfg.core-apps.enable {
-      environment.systemPackages = utils.removePackagesByName (
-        [
-          pkgs.baobab
-          pkgs.decibels
-          pkgs.epiphany
-          pkgs.gnome-text-editor
-          pkgs.gnome-calculator
-          pkgs.gnome-calendar
-          pkgs.gnome-characters
-          pkgs.gnome-clocks
-          pkgs.gnome-console
-          pkgs.gnome-contacts
-          pkgs.gnome-font-viewer
-          pkgs.gnome-logs
-          pkgs.gnome-maps
-          pkgs.gnome-music
-          pkgs.gnome-system-monitor
-          pkgs.gnome-weather
-          pkgs.loupe
-          pkgs.nautilus
-          pkgs.gnome-connections
-          pkgs.simple-scan
-          pkgs.snapshot
-          pkgs.totem
-          pkgs.yelp
-        ]
-        ++ lib.optionals config.services.flatpak.enable [
-          # Since PackageKit Nix support is not there yet,
-          # only install gnome-software if flatpak is enabled.
-          pkgs.gnome-software
-        ]
-      ) config.environment.gnome.excludePackages;
+      environment.systemPackages = utils.removePackagesByName [
+        pkgs.baobab
+        pkgs.decibels
+        pkgs.epiphany
+        pkgs.gnome-text-editor
+        pkgs.gnome-calculator
+        pkgs.gnome-calendar
+        pkgs.gnome-characters
+        pkgs.gnome-clocks
+        pkgs.gnome-console
+        pkgs.gnome-contacts
+        pkgs.gnome-font-viewer
+        pkgs.gnome-logs
+        pkgs.gnome-maps
+        pkgs.gnome-music
+        pkgs.gnome-system-monitor
+        pkgs.gnome-weather
+        pkgs.loupe
+        pkgs.nautilus
+        pkgs.gnome-connections
+        pkgs.simple-scan
+        pkgs.snapshot
+        pkgs.totem
+        pkgs.yelp
+      ] config.environment.gnome.excludePackages;
 
       # Enable default program modules
       # Since some of these have a corresponding package, we only
@@ -488,6 +481,12 @@ in
       programs.seahorse.enable = notExcluded pkgs.seahorse;
       services.gnome.sushi.enable = notExcluded pkgs.sushi;
 
+      # Since PackageKit Nix support is not there yet,
+      # only install gnome-software if flatpak is enabled.
+      services.gnome.gnome-software.enable = lib.mkIf config.services.flatpak.enable (
+        notExcluded pkgs.gnome-software
+      );
+
       # VTE shell integration for gnome-console
       programs.bash.vteIntegration = mkDefault true;
       programs.zsh.vteIntegration = mkDefault true;