### Godot version

v4.1.stable.official [970459615]

### System information

Godot v4.1.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1660 Ti (NVIDIA; 31.0.15.3598) - AMD Ryzen 7 3700X 8-Core Processor (16 Threads)

### Issue description

is_input_handled() is returning True, even though set_input_as_handled() has not been called.

Example:
`func _input_event(viewport, event, shape_idx):
	print(viewport.is_input_handled())`

Returns 'True', should return 'False'

### Steps to reproduce

1. Create a new project and add a Node2D as the root
2. Add a child Area2D node containing a CollisionShape2D and a Sprite2D
3. Either create the _input_event(viewport, event, shape_idx) or connect _on_input_event(viewport, event, shape_idx)
4. Print viewport.is_input_handled()
5. True is printed.

### Minimal reproduction project

[input_test.zip](https://github.com/godotengine/godot/files/12063748/input_test.zip)

ERR_READ_THREAD_GUARD_V(Ref<World2D>());
	if (world_2d.is_valid()) {
		return world_2d;
	} else if (parent) {
		return parent->find_world_2d();
	} else {
		return Ref<World2D>();
	}
}
void Viewport::_propagate_viewport_notification(Node *p_node, int p_what) {
	p_node->notification(p_what);
	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *c = p_node->get_child(i);
		if (Object::cast_to<Viewport>(c)) {
			continue;
		}
		_propagate_viewport_notification(c, p_what);
	}
}
Ref<World2D> Viewport::get_world_2d() const {
	ERR_READ_THREAD_GUARD_V(Ref<World2D>());
	return world_2d;
}
Camera2D *Viewport::get_camera_2d() const {