### 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 (_base) {
		return Ref<GDScript>(_base);
	} else {
		return Ref<Script>();
	}
}
StringName GDScript::get_global_name() const {
	return name;
}
StringName GDScript::get_instance_base_type() const {
	if (native.is_valid()) {
		return native->get_name();
	}
	if (base.is_valid() && base->is_valid()) {
		return base->get_instance_base_type();
	}
	return StringName();
}
struct _GDScriptMemberSort {
	int index = 0;
	StringName name;
	_FORCE_INLINE_ bool operator<(const _GDScriptMemberSort &p_member) const { return index < p_member.index; }
};
#ifdef TOOLS_ENABLED
void GDScript::_placeholder_erased(PlaceHolderScriptInstance *p_placeholder) {
	placeholders.erase(p_placeholder);
}
#endif
void GDScript::_get_script_method_list(List<MethodInfo> *r_list, bool p_include_base) const {