### 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.
return static_cast<LiteralNode *>(parse_literal(nullptr, false));
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_literal(ExpressionNode *p_previous_operand, bool p_can_assign) {
	if (previous.type != GDScriptTokenizer::Token::LITERAL) {
		push_error("Parser bug: parsing literal node without literal token.");
		ERR_FAIL_V_MSG(nullptr, "Parser bug: parsing literal node without literal token.");
	}
	LiteralNode *literal = alloc_node<LiteralNode>();
	complete_extents(literal);
	literal->value = previous.literal;
	return literal;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_self(ExpressionNode *p_previous_operand, bool p_can_assign) {
	if (current_function && current_function->is_static) {
		push_error(R"(Cannot use "self" inside a static function.)");
	}
	SelfNode *self = alloc_node<SelfNode>();
	complete_extents(self);
	self->current_class = current_class;
	return self;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_builtin_constant(ExpressionNode *p_previous_operand, bool p_can_assign) {