### 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.
SuiteNode *body = alloc_node<SuiteNode>();
	body->parent_function = current_function;
	body->parent_block = current_suite;
	SuiteNode *previous_suite = current_suite;
	current_suite = body;
	parse_function_signature(function, body, "lambda");
	current_suite = previous_suite;
	bool previous_in_lambda = in_lambda;
	in_lambda = true;
	function->body = parse_suite("lambda declaration", body, true);
	complete_extents(function);
	complete_extents(lambda);
	pop_multiline();
	if (multiline_context) {
		
		while (check(GDScriptTokenizer::Token::DEDENT) || check(GDScriptTokenizer::Token::INDENT) || check(GDScriptTokenizer::Token::NEWLINE)) {
			current = tokenizer.scan(); 
		}
		tokenizer.pop_expression_indented_block();
	}
	current_function = previous_function;
	in_lambda = previous_in_lambda;
	lambda->function = function;
	return lambda;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_yield(ExpressionNode *p_previous_operand, bool p_can_assign) {
	push_error(R"("yield" was removed in Godot 4.0. Use "await" instead.)");
	return nullptr;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_invalid_token(ExpressionNode *p_previous_operand, bool p_can_assign) {