### 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<StringName, GDScript::MemberInfo>::Iterator E = script->member_indices.find(p_name);
		if (E) {
			const GDScript::MemberInfo *member = &E->value;
			Variant value = p_value;
			if (member->data_type.has_type && !member->data_type.is_type(value)) {
				const Variant *args = &p_value;
				Callable::CallError err;
				Variant::construct(member->data_type.builtin_type, value, &args, 1, err);
				if (err.error != Callable::CallError::CALL_OK || !member->data_type.is_type(value)) {
					return false;