### 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.
ERR_FAIL_COND_V_MSG(!valid_annotations.has(p_annotation->name), false, vformat(R"(Annotation "%s" not found to validate.)", p_annotation->name));
	const MethodInfo &info = valid_annotations[p_annotation->name].info;
	if (((info.flags & METHOD_FLAG_VARARG) == 0) && p_annotation->arguments.size() > info.arguments.size()) {
		push_error(vformat(R"(Annotation "%s" requires at most %d arguments, but %d were given.)", p_annotation->name, info.arguments.size(), p_annotation->arguments.size()));
		return false;
	}
	if (p_annotation->arguments.size() < info.arguments.size() - info.default_arguments.size()) {
		push_error(vformat(R"(Annotation "%s" requires at least %d arguments, but %d were given.)", p_annotation->name, info.arguments.size() - info.default_arguments.size(), p_annotation->arguments.size()));
		return false;
	}
	
	if (p_annotation->name == SNAME("@icon")) {
		ExpressionNode *argument = p_annotation->arguments[0];
		if (argument->type != Node::LITERAL) {
			push_error(R"(Argument 1 of annotation "@icon" must be a string literal.)", argument);
			return false;
		}
		Variant value = static_cast<LiteralNode *>(argument)->value;
		if (value.get_type() != Variant::STRING) {
			push_error(R"(Argument 1 of annotation "@icon" must be a string literal.)", argument);
			return false;
		}
		p_annotation->resolved_arguments.push_back(value);
	}
	
	return true;
}
bool GDScriptParser::tool_annotation(const AnnotationNode *p_annotation, Node *p_node) {