### 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_MAIN_THREAD_GUARD;
	gui.canvas_sort_index = 0;
}
int Viewport::gui_get_canvas_sort_index() {
	ERR_MAIN_THREAD_GUARD_V(0);
	return gui.canvas_sort_index++;
}
void Viewport::gui_release_focus() {
	ERR_MAIN_THREAD_GUARD;
	if (gui.key_focus) {
		Control *f = gui.key_focus;
		gui.key_focus = nullptr;
		f->notification(Control::NOTIFICATION_FOCUS_EXIT, true);
		f->queue_redraw();
	}
}
Control *Viewport::gui_get_focus_owner() const {
	ERR_READ_THREAD_GUARD_V(nullptr);
	return gui.key_focus;
}
void Viewport::set_msaa_2d(MSAA p_msaa) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_INDEX(p_msaa, MSAA_MAX);
	if (msaa_2d == p_msaa) {
		return;
	}
	msaa_2d = p_msaa;
	RS::get_singleton()->viewport_set_msaa_2d(viewport, RS::ViewportMSAA(p_msaa));
}
Viewport::MSAA Viewport::get_msaa_2d() const {