### Godot version

4.1.dev

### System information

Win11

### Issue description

I load a non-existing GDScript, but it still returns a valid instance instead of null.
```gdscript
@tool
extends EditorScript

func _run():
	var s = ResourceLoader.load("non_exists.gd", "", ResourceLoader.CACHE_MODE_IGNORE)
	print(s)
	assert(s == null)

```

```
  Attempt to open script 'res://non_exists.gd' resulted in error 'File not found'.
<GDScript#-9223369015982753437>
  res://new_script.gd:7 - Assertion failed.

```

### Steps to reproduce

N/A

### Minimal reproduction project

N/A
#ifdef TOOLS_ENABLED
	bool cyclic_error = false;
	_update_exports(&cyclic_error);
	if (cyclic_error) {
		return;
	}
	HashSet<ObjectID> copy = inheriters_cache; 
	for (const ObjectID &E : copy) {
		Object *id = ObjectDB::get_instance(E);
		GDScript *s = Object::cast_to<GDScript>(id);
		if (!s) {
			continue;
		}
		s->update_exports();
	}
#endif
}
String GDScript::_get_debug_path() const {