### Godot version

4.0-rc1

### System information

Windows 10

### Issue description

The code: `@export @onready var camera_system : Node3D`

Is throwing: `Line 5:The "@onready" annotation will make the default value to be set after the "@export" takes effect and will override it. (Warning treated as error.)` and is crashing the game.

Unchecking "Treat Warning as Errors" seems to have no effect:

![imagen](https://user-images.githubusercontent.com/248383/217900756-8e214c40-68fb-4fb2-8509-a1e689725930.png)

![imagen](https://user-images.githubusercontent.com/248383/217901253-3b758ebc-48e9-40fe-8d77-16fce7cbae88.png)


### Steps to reproduce

- Write `@export @onready var some_var : Node3D`
- In Project Settings, uncheck `Treat Warning as Errors`
- Try to run the project, a `Parser Error` will be thrown.

### Minimal reproduction project

It's as simple as adding one line of code, so I'm not sure a MRP is needed.
int gcc = CoreConstants::get_global_constant_count();
	for (int i = 0; i < gcc; i++) {
		_add_global(StaticCString::create(CoreConstants::get_global_constant_name(i)), CoreConstants::get_global_constant_value(i));
	}
	_add_global(StaticCString::create("PI"), Math_PI);
	_add_global(StaticCString::create("TAU"), Math_TAU);
	_add_global(StaticCString::create("INF"), INFINITY);
	_add_global(StaticCString::create("NAN"), NAN);
	
	List<StringName> class_list;
	ClassDB::get_class_list(&class_list);
	for (const StringName &n : class_list) {
		if (globals.has(n)) {
			continue;
		}
		Ref<GDScriptNativeClass> nc = memnew(GDScriptNativeClass(n));
		_add_global(n, nc);
	}
	
	List<Engine::Singleton> singletons;
	Engine::get_singleton()->get_singletons(&singletons);
	for (const Engine::Singleton &E : singletons) {
		_add_global(E.name, E.ptr);
	}
#ifdef TESTS_ENABLED
	GDScriptTests::GDScriptTestRunner::handle_cmdline();
#endif
}
String GDScriptLanguage::get_type() const {