### 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.
HashMap<String, ObjectID>::Iterator orphan_subclass_element = orphan_subclasses.find(p_qualified_name);
	if (!orphan_subclass_element) {
		return Ref<GDScript>();
	}
	ObjectID orphan_subclass = orphan_subclass_element->value;
	Object *obj = ObjectDB::get_instance(orphan_subclass);
	orphan_subclasses.remove(orphan_subclass_element);
	if (!obj) {
		return Ref<GDScript>();
	}
	return Ref<GDScript>(Object::cast_to<GDScript>(obj));
}
Ref<GDScript> GDScriptLanguage::get_script_by_fully_qualified_name(const String &p_name) {
	{
		MutexLock lock(mutex);
		SelfList<GDScript> *elem = script_list.first();
		while (elem) {
			GDScript *scr = elem->self();
			if (scr->fully_qualified_name == p_name) {
				return scr;
			}
			elem = elem->next();
		}
	}
	Ref<GDScript> scr;
	scr.instantiate();
	scr->fully_qualified_name = p_name;
	return scr;
}
Ref<Resource> ResourceFormatLoaderGDScript::load(const String &p_path, const String &p_original_path, Error *r_error, bool p_use_sub_threads, float *r_progress, CacheMode p_cache_mode) {