### 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.
switch (mode) {
			case BRIEF:
				p_brief = (p_brief.length() == 0) ? doc_line : p_brief + line_join + doc_line;
				break;
			case DESC:
				p_desc = (p_desc.length() == 0) ? doc_line : p_desc + line_join + doc_line;
				break;
			case TUTORIALS:
				p_tutorials.append(Pair<String, String>(title, link));
				break;
			case DONE:
				break;
		}
	}
	if (current_class->members.size() > 0) {
		const ClassNode::Member &m = current_class->members[0];
		int first_member_line = m.get_line();
		if (first_member_line == line) {
			p_brief = "";
			p_desc = "";
			p_tutorials.clear();
		}
	}
}
#endif 
GDScriptParser::ParseRule *GDScriptParser::get_rule(GDScriptTokenizer::Token::Type p_token_type) {
	
	
	
	static ParseRule rules[] = {