### 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.
clear_data->functions.insert(implicit_initializer);
		implicit_initializer = nullptr;
	}
	if (implicit_ready) {
		clear_data->functions.insert(implicit_ready);
		implicit_ready = nullptr;
	}
	_save_orphaned_subclasses(clear_data);
#ifdef TOOLS_ENABLED
	
	if (_owner) {
		_clear_doc();
	}
#endif
	
	if (is_root) {
		
		for (GDScriptFunction *E : clear_data->functions) {
			memdelete(E);
		}
		for (Ref<Script> &E : clear_data->scripts) {
			Ref<GDScript> gdscr = E;
			if (gdscr.is_valid()) {
				GDScriptCache::remove_script(gdscr->get_path());
			}
		}
		clear_data->clear();
	}
}
GDScript::~GDScript() {