### 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)

if (audio_listener_2d == p_listener) {
		return;
	} else if (audio_listener_2d) {
		audio_listener_2d->clear_current();
	}
	audio_listener_2d = p_listener;
}
void Viewport::_audio_listener_2d_remove(AudioListener2D *p_listener) {
	if (audio_listener_2d == p_listener) {
		audio_listener_2d = nullptr;
	}
}
void Viewport::_canvas_layer_add(CanvasLayer *p_canvas_layer) {
	canvas_layers.insert(p_canvas_layer);
}
void Viewport::_canvas_layer_remove(CanvasLayer *p_canvas_layer) {
	canvas_layers.erase(p_canvas_layer);
}
void Viewport::set_transparent_background(bool p_enable) {
	ERR_MAIN_THREAD_GUARD;
	transparent_bg = p_enable;
	RS::get_singleton()->viewport_set_transparent_background(viewport, p_enable);
}
bool Viewport::has_transparent_background() const {
	ERR_READ_THREAD_GUARD_V(false);
	return transparent_bg;
}
void Viewport::set_world_2d(const Ref<World2D> &p_world_2d) {