Revert "update default username"

This reverts commit 1be00fd.

Author: tibtiq

checks/username.nix

@@ -8,7 +8,7 @@ let
   baseModule = { ... }: {
     imports = [ ../modules ];
     wsl.enable = true;
-    wsl.defaultUser = "nixos-wsl";
+    wsl.defaultUser = "nixos";
   };
   changedUsername = { lib, ... }: {
     wsl.defaultUser = lib.mkForce "different";

modules/build-tarball.nix

@@ -30,7 +30,7 @@ let
       ];
 
       wsl.enable = true;
-      wsl.defaultUser = "nixos-wsl";
+      wsl.defaultUser = "nixos";
 
       # This value determines the NixOS release from which the default
       # settings for stateful data, like file locations and database versions