Incorrect OS.get_cmdline_args() usage example

[pwajnkaim]

Your Godot version:
4.4.1

Issue description:
In the documentation for OS.get_cmdline_user_args(), an example usage of OS.get_cmdline_args() shows it returning --fullscreen. If you try this yourself, godot won't actually return --fullscreen or any other inbuilt engine arguments I could find.

It's a little unclear if this is intended behavior: godotengine/godot#92831
If it is, the documentation for OS.get_cmdline_args() should also state it explicitly.

URL to the documentation page:
https://docs.godotengine.org/en/stable/classes/class_os.html#class-os-method-get-cmdline-user-args