### 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.
#ifdef DEBUG_ENABLED
	List<Ref<GDScript>> scripts;
	{
		MutexLock lock(this->mutex);
		SelfList<GDScript> *elem = script_list.first();
		while (elem) {
			
			if (elem->self()->is_root_script() && elem->self()->get_path().is_resource_file()) {
				scripts.push_back(Ref<GDScript>(elem->self())); 
			}
			elem = elem->next();
		}
	}
	
	HashMap<Ref<GDScript>, HashMap<ObjectID, List<Pair<StringName, Variant>>>> to_reload;
	
	scripts.sort_custom<GDScriptDepSort>(); 
	for (Ref<GDScript> &scr : scripts) {
		bool reload = scr == p_script || to_reload.has(scr->get_base());
		if (!reload) {
			continue;
		}
		to_reload.insert(scr, HashMap<ObjectID, List<Pair<StringName, Variant>>>());
		if (!p_soft_reload) {