### 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.
script_frame_time = 0;
	_debug_call_stack_pos = 0;
	int dmcs = GLOBAL_DEF(PropertyInfo(Variant::INT, "debug/settings/gdscript/max_call_stack", PROPERTY_HINT_RANGE, "1024,4096,1,or_greater"), 1024);
	if (EngineDebugger::is_active()) {
		
		_debug_max_call_stack = dmcs;
		_call_stack = memnew_arr(CallLevel, _debug_max_call_stack + 1);
	} else {
		_debug_max_call_stack = 0;
		_call_stack = nullptr;
	}
#ifdef DEBUG_ENABLED
	GLOBAL_DEF("debug/gdscript/warnings/enable", true);
	GLOBAL_DEF("debug/gdscript/warnings/treat_warnings_as_errors", false);
	GLOBAL_DEF("debug/gdscript/warnings/exclude_addons", true);
	for (int i = 0; i < (int)GDScriptWarning::WARNING_MAX; i++) {
		GDScriptWarning::Code code = (GDScriptWarning::Code)i;
		Variant default_enabled = GDScriptWarning::get_default_value(code);
		String path = GDScriptWarning::get_settings_path_from_code(code);
		GLOBAL_DEF(GDScriptWarning::get_property_info(code), default_enabled);
	}
#endif 
}
GDScriptLanguage::~GDScriptLanguage() {
	singleton = nullptr;
}
void GDScriptLanguage::add_orphan_subclass(const String &p_qualified_name, const ObjectID &p_subclass) {
	orphan_subclasses[p_qualified_name] = p_subclass;
}
Ref<GDScript> GDScriptLanguage::get_orphan_subclass(const String &p_qualified_name) {