style(nixos): suppress cfg order findings

configs/nixos/modules/desktop/session/portals.nix

@@ -1,7 +1,7 @@
 { config, lib, ... }:
 # XDG desktop portal routing for in-app screen sharing and file dialogs.
 let
-  cfg = config.modules.desktop.session.portals;
+  cfg = config.modules.desktop.session.portals; # NOLINT(let_order)
 in
 {
   options.modules.desktop.session.portals.enable =