refactor(waybar): store rendered window icons

configs/nixos/modules/desktop/session/hyprland/default.nix

@@ -4,9 +4,6 @@
   ...
 }:
 # The Hyprland compositor.
-let
-  glyph = code: builtins.fromJSON ''"\u${code}"'';
-in
 {
   options.modules.desktop.session.hyprland.enable = lib.mkEnableOption "the Hyprland compositor";
 
@@ -238,9 +235,9 @@ in
         on-click = "activate";
         format = "{id} {windows}";
         format-window-separator = " ";
-        window-rewrite-default = glyph "f2d0";
+        window-rewrite-default = builtins.fromJSON ''"\uf2d0"'';
         window-rewrite = lib.mapAttrs' (
-          _name: windowIcon: lib.nameValuePair "class<${windowIcon.class}>" (glyph windowIcon.icon)
+          _name: windowIcon: lib.nameValuePair "class<${windowIcon.class}>" windowIcon.icon
         ) (lib.attrByPath [ config.networking.hostName ] { } config.registry.window-icon);
       };
     };