users: Add system.singleUser

modules/programs/zsh/default.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ config, pkgs, ... }:
 
 {
   environment = {
@@ -11,7 +11,7 @@
   # Otherwise the user won't appear on the GDM login screen
   programs.zsh.enable = true;
 
-  home-manager.users.alexander.programs.zsh = {
+  home-manager.users."${config.system.singleUser}".programs.zsh = {
     enable = true;
     history.ignoreSpace = true;
     shellAliases = {