demo-iso: fix evaluation warning

flakeModules/demo_iso.nix

@@ -45,7 +45,9 @@ let
     '';
   };
 
-  morphModule = {
+  morphModule =
+    { config, ... }:
+    {
       imports = [
         (
           { modulesPath, ... }:
@@ -67,6 +69,8 @@ let
           ${clan_welcome}/bin/clan_welcome
         fi
       '';
+
+      system.stateVersion = config.system.nixos.release;
     };
 in
 {