nixos/uwsm: remove dependency on services.displayManager (#489812)

      {

        environment.systemPackages = [ cfg.package ];

        systemd.packages = [ cfg.package ];

        environment.pathsToLink = [ "/share/uwsm" ];

        environment.pathsToLink = [

          "/share/uwsm"

          "/share/wayland-sessions"

        ];

        # UWSM recommends dbus broker for better compatibility

        services.dbus.implementation = "broker";

      }

      (lib.mkIf (cfg.waylandCompositors != { }) {

        services.displayManager.sessionPackages = lib.mapAttrsToList (

        environment.systemPackages = lib.mapAttrsToList (

          name: value:

          mk_uwsm_desktop_entry {

            inherit name;