### 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 ERR_PARSE_ERROR;
	}
	bool can_run = ScriptServer::is_scripting_enabled() || parser.is_tool();
	GDScriptCompiler compiler;
	err = compiler.compile(&parser, this, p_keep_state);
	if (err) {
		if (can_run) {
			if (EngineDebugger::is_active()) {
				GDScriptLanguage::get_singleton()->debug_break_parse(_get_debug_path(), compiler.get_error_line(), "Parser Error: " + compiler.get_error());
			}
			_err_print_error("GDScript::reload", path.is_empty() ? "built-in" : (const char *)path.utf8().get_data(), compiler.get_error_line(), ("Compile Error: " + compiler.get_error()).utf8().get_data(), false, ERR_HANDLER_SCRIPT);
			reloading = false;
			return ERR_COMPILATION_FAILED;
		} else {
			reloading = false;
			return err;
		}
	}
#ifdef DEBUG_ENABLED
	for (const GDScriptWarning &warning : parser.get_warnings()) {
		if (EngineDebugger::is_active()) {
			Vector<ScriptLanguage::StackInfo> si;
			EngineDebugger::get_script_debugger()->send_error("", get_script_path(), warning.start_line, warning.get_name(), warning.get_message(), false, ERR_HANDLER_WARNING, si);
		}
	}
#endif
	reloading = false;
	return OK;
}
ScriptLanguage *GDScript::get_language() const {