global/nix: clean up

modules/global/nix.nix

@@ -1,5 +1,7 @@
-{ config, channel, inputs, pkgs, lib, self, ... }:
-with lib;
+{ config, inputs, pkgs, lib, ... }:
+let
+  inherit (lib) mkIf mkDefault filterAttrs mapAttrs';
+in
 {
   nix = {
     package = pkgs.nixVersions.latest;
@@ -78,6 +80,7 @@ with lib;
     nix-melt
     nix-output-monitor
     nix-tree
+    nixfmt-rfc-style
     nixpkgs-fmt
     nvd
 
@@ -92,10 +95,7 @@ with lib;
   ];
 
   environment = {
-    shellAliases =
-      let ifSudo = mkIf config.security.sudo.enable;
-      in
-      {
+    shellAliases = {
       # nix
       n = "nix";
       ns = "n search --no-update-lock-file";