### Godot version

4.0.3.stable

### System information

windows 11

### Issue description

fullscreen on the window node is not working and will show up as a windowed.

### Steps to reproduce

disable Embed Subwindows in Project Settings/Display/Window.
create a window node and set its mode to fullscreen.

### Minimal reproduction project

[fullscreen.zip](https://github.com/godotengine/godot/files/11821834/fullscreen.zip)
if (theme_icon_override.has(dname)) {
				theme_icon_override[dname]->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
			}
			theme_icon_override.erase(dname);
			_notify_theme_override_changed();
		} else if (name.begins_with("theme_override_styles/")) {
			String dname = name.get_slicec('/', 1);
			if (theme_style_override.has(dname)) {
				theme_style_override[dname]->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
			}
			theme_style_override.erase(dname);
			_notify_theme_override_changed();
		} else if (name.begins_with("theme_override_fonts/")) {
			String dname = name.get_slicec('/', 1);
			if (theme_font_override.has(dname)) {
				theme_font_override[dname]->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
			}
			theme_font_override.erase(dname);
			_notify_theme_override_changed();
		} else if (name.begins_with("theme_override_font_sizes/")) {
			String dname = name.get_slicec('/', 1);
			theme_font_size_override.erase(dname);
			_notify_theme_override_changed();
		} else if (name.begins_with("theme_override_colors/")) {
			String dname = name.get_slicec('/', 1);
			theme_color_override.erase(dname);
			_notify_theme_override_changed();
		} else if (name.begins_with("theme_override_constants/")) {
			String dname = name.get_slicec('/', 1);
			theme_constant_override.erase(dname);