### 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<ObjectID, List<Pair<StringName, Variant>>> &map = to_reload[scr];
			while (scr->instances.front()) {
				Object *obj = scr->instances.front()->get();
				
				List<Pair<StringName, Variant>> state;
				if (obj->get_script_instance()) {
					obj->get_script_instance()->get_property_state(state);
					map[obj->get_instance_id()] = state;
					obj->set_script(Variant());
				}
			}
#ifdef TOOLS_ENABLED
			while (scr->placeholders.size()) {
				Object *obj = (*scr->placeholders.begin())->get_owner();
				
				if (obj->get_script_instance()) {
					map.insert(obj->get_instance_id(), List<Pair<StringName, Variant>>());
					List<Pair<StringName, Variant>> &state = map[obj->get_instance_id()];
					obj->get_script_instance()->get_property_state(state);
					obj->set_script(Variant());
				} else {
					
					scr->placeholders.erase(*scr->placeholders.begin());
				}
			}
#endif
			for (const KeyValue<ObjectID, List<Pair<StringName, Variant>>> &F : scr->pending_reload_state) {
				map[F.key] = F.value; 
			}