### 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.
for (const KeyValue<StringName, Vector<StringName>> &E : _signals) {
		MethodInfo mi;
		mi.name = E.key;
		for (int i = 0; i < E.value.size(); i++) {
			PropertyInfo arg;
			arg.name = E.value[i];
			mi.arguments.push_back(arg);
		}
		r_list->push_back(mi);
	}
	if (!p_include_base) {
		return;
	}
	if (base.is_valid()) {
		base->get_script_signal_list(r_list);
	}
#ifdef TOOLS_ENABLED
	else if (base_cache.is_valid()) {
		base_cache->get_script_signal_list(r_list);
	}
#endif
}
void GDScript::get_script_signal_list(List<MethodInfo> *r_signals) const {