### 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.
ClassNode *n_class = alloc_node<ClassNode>();
	ClassNode *previous_class = current_class;
	current_class = n_class;
	n_class->outer = previous_class;
	if (consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected identifier for the class name after "class".)")) {
		n_class->identifier = parse_identifier();
		if (n_class->outer) {
			String fqcn = n_class->outer->fqcn;
			if (fqcn.is_empty()) {
				fqcn = script_path;
			}
			n_class->fqcn = fqcn + "::" + n_class->identifier->name;
		} else {
			n_class->fqcn = n_class->identifier->name;
		}
	}
	if (match(GDScriptTokenizer::Token::EXTENDS)) {
		parse_extends();
	}
	consume(GDScriptTokenizer::Token::COLON, R"(Expected ":" after class declaration.)");
	bool multiline = match(GDScriptTokenizer::Token::NEWLINE);
	if (multiline && !consume(GDScriptTokenizer::Token::INDENT, R"(Expected indented block after class declaration.)")) {
		current_class = previous_class;
		complete_extents(n_class);
		return n_class;