### 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.
_base = nullptr;
				ERR_FAIL_V_MSG(false, "Cyclic inheritance in script class.");
			}
		}
		if (base_cache->_update_exports(r_err, true)) {
			if (r_err && *r_err) {
				return false;
			}
			changed = true;
		}
	}
	if ((changed || p_instance_to_update) && placeholders.size()) { 
		
		HashMap<StringName, Variant> values;
		List<PropertyInfo> propnames;
		_update_exports_values(values, propnames);
		if (changed) {
			for (PlaceHolderScriptInstance *E : placeholders) {
				E->update(propnames, values);
			}
		} else {
			p_instance_to_update->update(propnames, values);
		}
	}
	return changed;
#else
	return false;
#endif
}
void GDScript::update_exports() {