### 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.
const GDScript *sptr = script.ptr();
	while (sptr) {
		for (const KeyValue<StringName, GDScriptFunction *> &E : sptr->member_functions) {
			MethodInfo mi;
			mi.name = E.key;
			for (int i = 0; i < E.value->get_argument_count(); i++) {
				mi.arguments.push_back(PropertyInfo(Variant::NIL, "arg" + itos(i)));
			}
			p_list->push_back(mi);
		}
		sptr = sptr->_base;
	}
}
bool GDScriptInstance::has_method(const StringName &p_method) const {
	const GDScript *sptr = script.ptr();
	while (sptr) {
		HashMap<StringName, GDScriptFunction *>::ConstIterator E = sptr->member_functions.find(p_method);
		if (E) {
			return true;
		}
		sptr = sptr->_base;
	}
	return false;
}
Variant GDScriptInstance::callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) {