### 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.
set_last_completion_call_arg(argument_index++);
				ExpressionNode *argument = parse_expression(false);
				if (argument == nullptr) {
					valid = false;
					continue;
				}
				annotation->arguments.push_back(argument);
			} while (match(GDScriptTokenizer::Token::COMMA));
			pop_multiline();
			consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, R"*(Expected ")" after annotation arguments.)*");
		}
		pop_completion_call();
	}
	complete_extents(annotation);
	match(GDScriptTokenizer::Token::NEWLINE); 
	if (valid) {
		valid = validate_annotation_arguments(annotation);
	}
	return valid ? annotation : nullptr;
}
void GDScriptParser::clear_unused_annotations() {
	for (const AnnotationNode *annotation : annotation_stack) {
		push_error(vformat(R"(Annotation "%s" does not precedes a valid target, so it will have no effect.)", annotation->name), annotation);
	}
	annotation_stack.clear();
}
bool GDScriptParser::register_annotation(const MethodInfo &p_info, uint32_t p_target_kinds, AnnotationAction p_apply, const Vector<Variant> &p_default_arguments, bool p_is_vararg) {
	ERR_FAIL_COND_V_MSG(valid_annotations.has(p_info.name), false, vformat(R"(Annotation "%s" already registered.)", p_info.name));
	AnnotationInfo new_annotation;
	new_annotation.info = p_info;