### 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(nullptr);
	ERR_FAIL_COND_V(!is_inside_tree(), nullptr);
	if (!get_parent()) {
		return nullptr; 
	}
	return get_parent()->get_viewport();
}
void Viewport::set_embedding_subwindows(bool p_embed) {
	ERR_THREAD_GUARD;
	gui.embed_subwindows_hint = p_embed;
}
bool Viewport::is_embedding_subwindows() const {
	ERR_READ_THREAD_GUARD_V(false);
	return gui.embed_subwindows_hint;
}
void Viewport::subwindow_set_popup_safe_rect(Window *p_window, const Rect2i &p_rect) {
	int index = _sub_window_find(p_window);
	ERR_FAIL_COND(index == -1);
	SubWindow sw = gui.sub_windows[index];
	sw.parent_safe_rect = p_rect;
}
Rect2i Viewport::subwindow_get_popup_safe_rect(Window *p_window) const {
	int index = _sub_window_find(p_window);
	ERR_FAIL_COND_V(index == -1, Rect2i());
	return gui.sub_windows[index].parent_safe_rect;
}
void Viewport::pass_mouse_focus_to(Viewport *p_viewport, Control *p_control) {