### 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.
if (p_constants) {
		for (const KeyValue<StringName, Variant> &E : constants) {
			(*p_constants)[E.key] = E.value;
		}
	}
}
void GDScript::get_members(HashSet<StringName> *p_members) {
	if (p_members) {
		for (const StringName &E : members) {
			p_members->insert(E);
		}
	}
}
const Variant GDScript::get_rpc_config() const {
	return rpc_config;
}
Variant GDScript::callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) {
	GDScript *top = this;
	while (top) {
		HashMap<StringName, GDScriptFunction *>::Iterator E = top->member_functions.find(p_method);
		if (E) {
			ERR_FAIL_COND_V_MSG(!E->value->is_static(), Variant(), "Can't call non-static function '" + String(p_method) + "' in script.");
			return E->value->call(nullptr, p_args, p_argcount, r_error);
		}
		top = top->_base;
	}
	
	return Script::callp(p_method, p_args, p_argcount, r_error);
}
bool GDScript::_get(const StringName &p_name, Variant &r_ret) const {