### 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 (signal->parameters_indices.has(parameter->identifier->name)) {
				push_error(vformat(R"(Parameter with name "%s" was already declared for this signal.)", parameter->identifier->name));
			} else {
				signal->parameters_indices[parameter->identifier->name] = signal->parameters.size();
				signal->parameters.push_back(parameter);
			}
		} while (match(GDScriptTokenizer::Token::COMMA) && !is_at_end());
		pop_multiline();
		consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, R"*(Expected closing ")" after signal parameters.)*");
	}
	complete_extents(signal);
	end_statement("signal declaration");
	return signal;
}
GDScriptParser::EnumNode *GDScriptParser::parse_enum() {
	EnumNode *enum_node = alloc_node<EnumNode>();
	bool named = false;
	if (check(GDScriptTokenizer::Token::IDENTIFIER)) {
		advance();
		enum_node->identifier = parse_identifier();
		named = true;
	}
	push_multiline(true);
	consume(GDScriptTokenizer::Token::BRACE_OPEN, vformat(R"(Expected "{" after %s.)", named ? "enum name" : R"("enum")"));
	HashMap<StringName, int> elements;
#ifdef DEBUG_ENABLED
	List<MethodInfo> gdscript_funcs;
	GDScriptLanguage::get_singleton()->get_public_functions(&gdscript_funcs);
#endif
	do {