`is-windows?` is being highlighted as if it is a system variable

There is no `is-windows?` in the [NetLogo Dictionary](https://docs.netlogo.org/dictionary.html).

<img width="582" height="574" alt="Image" src="https://github.com/user-attachments/assets/3030595a-f227-4255-9a96-360289665dd9" />