Avoid possible infinite recursion

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/user/configs/gui/kitty/default.nix

@@ -1,5 +1,5 @@
 {
-  user ? throw "user argument is required",
+  username ? throw "username argument is required",
 }:
 {
   config,
@@ -8,10 +8,11 @@
   ...
 }:
 let
-  hmConfig = config.home-manager.users.${user.name};
+  userConfig = config.users.users.${username};
+  hmConfig = config.home-manager.users.${username};
 in
 {
-  home-manager.users.${user.name} = {
+  home-manager.users.${username} = {
     programs = {
       kitty = {
         enable = true;
@@ -44,6 +45,8 @@ in
       )
     } &";
 
-    home.persistence."/cache${user.home}".directories = [ "${hmConfig.xdg.relativeCacheHome}/kitty" ];
+    home.persistence."/cache${userConfig.home}".directories = [
+      "${hmConfig.xdg.relativeCacheHome}/kitty"
+    ];
   };
 }