### 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.
return nullptr;
	}
	complete_extents(constant);
	end_statement("constant declaration");
	return constant;
}
GDScriptParser::ParameterNode *GDScriptParser::parse_parameter() {
	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected parameter name.)")) {
		return nullptr;
	}
	ParameterNode *parameter = alloc_node<ParameterNode>();
	parameter->identifier = parse_identifier();
	if (match(GDScriptTokenizer::Token::COLON)) {
		if (check((GDScriptTokenizer::Token::EQUAL))) {
			
			parameter->infer_datatype = true;
		} else {
			
			make_completion_context(COMPLETION_TYPE_NAME, parameter);
			parameter->datatype_specifier = parse_type();
		}
	}
	if (match(GDScriptTokenizer::Token::EQUAL)) {
		
		parameter->initializer = parse_expression(false);
	}
	complete_extents(parameter);
	return parameter;
}
GDScriptParser::SignalNode *GDScriptParser::parse_signal() {