lxqt: use default qt5 and libsForQt5

pkgs/top-level/all-packages.nix

@@ -26455,10 +26455,8 @@ in
   lumina = recurseIntoAttrs (callPackage ../desktops/lumina { });
 
   lxqt = recurseIntoAttrs (import ../desktops/lxqt {
-    # TODO: Update these to qt515 at some point. When doing it, please remove
-    # the choice of libsForQt5*.sddm in sddm's module.
-    qt5 = qt514;
-    libsForQt5 = libsForQt514;
+    inherit qt5;
+    inherit libsForQt5;
     inherit pkgs;
     inherit (lib) makeScope;
   });