### 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.
if (parameter->initializer != nullptr) {
				default_used = true;
			} else {
				if (default_used) {
					push_error("Cannot have a mandatory parameters after optional parameters.");
					continue;
				}
			}
			if (p_function->parameters_indices.has(parameter->identifier->name)) {
				push_error(vformat(R"(Parameter with name "%s" was already declared for this %s.)", parameter->identifier->name, p_type));
			} else {
				p_function->parameters_indices[parameter->identifier->name] = p_function->parameters.size();
				p_function->parameters.push_back(parameter);
				p_body->add_local(parameter, current_function);
			}
		} while (match(GDScriptTokenizer::Token::COMMA));
	}
	pop_multiline();
	consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, vformat(R"*(Expected closing ")" after %s parameters.)*", p_type));
	if (match(GDScriptTokenizer::Token::FORWARD_ARROW)) {
		make_completion_context(COMPLETION_TYPE_NAME_OR_VOID, p_function);
		p_function->return_type = parse_type(true);
		if (p_function->return_type == nullptr) {
			push_error(R"(Expected return type or "void" after "->".)");
		}
	}
	
	consume(GDScriptTokenizer::Token::COLON, vformat(R"(Expected ":" after %s declaration.)", p_type));
}
GDScriptParser::FunctionNode *GDScriptParser::parse_function() {