### 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.
const GDScript *sptr = script.ptr();
	List<PropertyInfo> props;
	while (sptr) {
		HashMap<StringName, GDScriptFunction *>::ConstIterator E = sptr->member_functions.find(GDScriptLanguage::get_singleton()->strings._get_property_list);
		if (E) {
			Callable::CallError err;
			Variant ret = const_cast<GDScriptFunction *>(E->value)->call(const_cast<GDScriptInstance *>(this), nullptr, 0, err);
			if (err.error == Callable::CallError::CALL_OK) {
				ERR_FAIL_COND_MSG(ret.get_type() != Variant::ARRAY, "Wrong type for _get_property_list, must be an array of dictionaries.");
				Array arr = ret;
				for (int i = 0; i < arr.size(); i++) {
					Dictionary d = arr[i];
					ERR_CONTINUE(!d.has("name"));
					ERR_CONTINUE(!d.has("type"));
					PropertyInfo pinfo;
					pinfo.type = Variant::Type(d["type"].operator int());
					ERR_CONTINUE(pinfo.type < 0 || pinfo.type >= Variant::VARIANT_MAX);