### 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.
owner = nullptr;
	base_ref_counted = false;
}
GDScriptInstance::~GDScriptInstance() {
	MutexLock lock(GDScriptLanguage::get_singleton()->mutex);
	while (SelfList<GDScriptFunctionState> *E = pending_func_states.first()) {
		
		
		pending_func_states.remove(E);
		GDScriptFunctionState *state = E->self();
		ObjectID state_id = state->get_instance_id();
		state->_clear_connections();
		if (ObjectDB::get_instance(state_id)) {
			state->_clear_stack();
		}
	}
	if (script.is_valid() && owner) {
		script->instances.erase(owner);
	}
}
GDScriptLanguage *GDScriptLanguage::singleton = nullptr;
String GDScriptLanguage::get_name() const {
	return "GDScript";
}
void GDScriptLanguage::_add_global(const StringName &p_name, const Variant &p_value) {