### 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.
clear();
	String source = p_source_code;
	int cursor_line = -1;
	int cursor_column = -1;
	for_completion = p_for_completion;
	int tab_size = 4;
#ifdef TOOLS_ENABLED
	if (EditorSettings::get_singleton()) {
		tab_size = EditorSettings::get_singleton()->get_setting("text_editor/behavior/indent/size");
	}
#endif 
	if (p_for_completion) {
		
		const Vector<String> lines = p_source_code.split("\n");
		cursor_line = 1;
		cursor_column = 1;
		for (int i = 0; i < lines.size(); i++) {
			bool found = false;
			const String &line = lines[i];
			for (int j = 0; j < line.size(); j++) {
				if (line[j] == char32_t(0xFFFF)) {
					found = true;
					break;
				} else if (line[j] == '\t') {
					cursor_column += tab_size - 1;
				}
				cursor_column++;
			}