### 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)

#include "viewport.h"
#include "core/config/project_settings.h"
#include "core/debugger/engine_debugger.h"
#include "core/object/message_queue.h"
#include "core/string/translation.h"
#include "core/templates/pair.h"
#include "core/templates/sort_array.h"
#include "scene/2d/audio_listener_2d.h"
#include "scene/2d/camera_2d.h"
#include "scene/2d/collision_object_2d.h"
#ifndef _3D_DISABLED
#include "scene/3d/audio_listener_3d.h"
#include "scene/3d/camera_3d.h"
#include "scene/3d/collision_object_3d.h"
#include "scene/3d/world_environment.h"
#endif 
#include "scene/gui/control.h"
#include "scene/gui/label.h"
#include "scene/gui/popup.h"
#include "scene/gui/popup_menu.h"
#include "scene/gui/subviewport_container.h"
#include "scene/main/canvas_layer.h"
#include "scene/main/window.h"