### 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 *base_src = p_script->_base;
	if (base_src != nullptr) {
		_super_implicit_constructor(base_src, p_instance, r_error);
		if (r_error.error != Callable::CallError::CALL_OK) {
			return;
		}
	}
	ERR_FAIL_NULL(p_script->implicit_initializer);
	p_script->implicit_initializer->call(p_instance, nullptr, 0, r_error);
}
GDScriptInstance *GDScript::_create_instance(const Variant **p_args, int p_argcount, Object *p_owner, bool p_is_ref_counted, Callable::CallError &r_error) {
	
	GDScriptInstance *instance = memnew(GDScriptInstance);
	instance->base_ref_counted = p_is_ref_counted;
	instance->members.resize(member_indices.size());
	instance->script = Ref<GDScript>(this);
	instance->owner = p_owner;
	instance->owner_id = p_owner->get_instance_id();
#ifdef DEBUG_ENABLED
	
	for (const KeyValue<StringName, MemberInfo> &E : member_indices) {
		instance->member_indices_cache[E.key] = E.value.index;
	}
#endif
	instance->owner->set_script_instance(instance);
	
	{
		MutexLock lock(GDScriptLanguage::singleton->mutex);
		instances.insert(instance->owner);
	}