### 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.
{ nullptr,                                          &GDScriptParser::parse_attribute,            	PREC_ATTRIBUTE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ &GDScriptParser::parse_get_node,               	nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		
		{ &GDScriptParser::parse_builtin_constant,			nullptr,                                        PREC_NONE }, 
		{ &GDScriptParser::parse_builtin_constant,			nullptr,                                        PREC_NONE }, 
		{ &GDScriptParser::parse_builtin_constant,			nullptr,                                        PREC_NONE }, 
		{ &GDScriptParser::parse_builtin_constant,			nullptr,                                        PREC_NONE }, 
		
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          &GDScriptParser::parse_invalid_token,        	PREC_CAST }, 
		
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
		{ nullptr,                                          nullptr,                                        PREC_NONE }, 
	};
	
	
	static_assert(sizeof(rules) / sizeof(rules[0]) == GDScriptTokenizer::Token::TK_MAX, "Amount of parse rules don't match the amount of token types.");
	
	return &rules[p_token_type];
}
bool GDScriptParser::SuiteNode::has_local(const StringName &p_name) const {