### 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.
*   it should attempt its best to retrieve the inheritance metadata.
	 *
	 * Before changing this function, please ask the current maintainer of EditorFileSystem.
	 */
	if (r_icon_path) {
		if (c->icon_path.is_empty() || c->icon_path.is_absolute_path()) {
			*r_icon_path = c->icon_path.simplify_path();
		} else if (c->icon_path.is_relative_path()) {
			*r_icon_path = p_path.get_base_dir().path_join(c->icon_path).simplify_path();
		}
	}
	if (r_base_type) {
		const GDScriptParser::ClassNode *subclass = c;
		String path = p_path;
		GDScriptParser subparser;
		while (subclass) {
			if (subclass->extends_used) {
				if (!subclass->extends_path.is_empty()) {
					if (subclass->extends.size() == 0) {
						get_global_class_name(subclass->extends_path, r_base_type);
						subclass = nullptr;
						break;
					} else {
						Vector<StringName> extend_classes = subclass->extends;
						Ref<FileAccess> subfile = FileAccess::open(subclass->extends_path, FileAccess::READ);
						if (subfile.is_null()) {
							break;
						}
						String subsource = subfile->get_as_utf8_string();
						if (subsource.is_empty()) {