### Godot version

v4.1.2.rc1.official [58f0cae4a] and v4.2.dev5.official [e3e2528ba]

### System information

Godot v4.1.2.rc1 - Windows 10.0.19044 - Vulkan (Compatibility) - NVIDIA GeForce GTX 1650 (NVIDIA; 31.0.15.3742) - AMD Ryzen 5 3550H with Radeon Vega Mobile Gfx (8 Threads)

### Issue description

Clearing one of the values of a typed array in the inspector seems to just unreference value and not set it to `<null>`, so the value becomes `<Object#null>`. Array's find function seems to look for the `<null>` value and doesn't accept `<Object#null>`, even if in GDScript `<Object#null>` == `<null>`. So, when calling array.find(null) in the tool script, the function can't find anything. When the project is restarted or you run it, the values that were equal to `<Object#null>` will become `<null>`.
![image](https://github.com/godotengine/godot/assets/118438257/208dbf2c-19ea-4d97-9e46-646662cb5122)

### Steps to reproduce

1. Export a typed array of Resource or any of the types that inherit from it;
2. Set one of the values of a typed array to anything;
3. Clear the value;
4. Use array.find(null) in any of the tool scripts.

### Minimal reproduction project

[ArrayBug.zip](https://github.com/godotengine/godot/files/12789530/ArrayBug.zip)
Button *button = Object::cast_to<Button>(p_button);
	Rect2 rect = button->get_screen_rect();
	change_type->set_item_disabled(change_type->get_item_index(Variant::VARIANT_MAX), p_index < 0);
	change_type->reset_size();
	change_type->set_position(rect.get_end() - Vector2(change_type->get_contents_minimum_size().x, 0));
	change_type->popup();
	changing_type_index = p_index;
}
void EditorPropertyDictionary::_add_key_value() {
	
	if (object->get_new_item_key().get_type() == Variant::NIL) {
		return;
	}
	Dictionary dict = object->get_dict().duplicate();
	dict[object->get_new_item_key()] = object->get_new_item_value();
	object->set_new_item_key(Variant());
	object->set_new_item_value(Variant());
	emit_changed(get_edited_property(), dict, "", false);
	update_property();
}
void EditorPropertyDictionary::_change_type_menu(int p_index) {