feat: Allow input from derivation

outputs/homeConfigurations.nix

@@ -16,10 +16,10 @@ let users = builtins.readDir ../users;
 
         # TODO: Move to default module.
         ({ lib, ... }: {
-          nix = {
-            settings.experimental-features =
-              lib.mkDefault
-                [ "nix-command" "flakes" ];
+          nix.settings = {
+            experimental-features =
+              lib.mkDefault [ "nix-command" "flakes" ];
+            allow-import-from-derivation = true;
           };
         })
       ];