### 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.
GDScript *sptr = script.ptr();
	if (unlikely(p_method == SNAME("_ready"))) {
		
		while (sptr) {
			if (sptr->implicit_ready) {
				sptr->implicit_ready->call(this, nullptr, 0, r_error);
			}
			sptr = sptr->_base;
		}
		
		sptr = script.ptr();
	}
	while (sptr) {
		HashMap<StringName, GDScriptFunction *>::Iterator E = sptr->member_functions.find(p_method);
		if (E) {
			return E->value->call(this, p_args, p_argcount, r_error);
		}
		sptr = sptr->_base;
	}
	r_error.error = Callable::CallError::CALL_ERROR_INVALID_METHOD;
	return Variant();
}
void GDScriptInstance::notification(int p_notification) {