### 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)

break;
						}
					}
					if (ci->is_set_as_top_level()) {
						break;
					}
					ci = ci->get_parent_item();
				}
			}
			bool stopped = gui.mouse_focus && gui.mouse_focus->can_process() && _gui_call_input(gui.mouse_focus, mb);
			if (stopped) {
				set_input_as_handled();
			}
			if (gui.dragging && mb->get_button_index() == MouseButton::LEFT) {
				
				_perform_drop(gui.mouse_focus, pos);
			}
			_gui_cancel_tooltip();
		} else {
			if (gui.dragging && mb->get_button_index() == MouseButton::LEFT) {
				_perform_drop(gui.drag_mouse_over, gui.drag_mouse_over_pos);
			}
			gui.mouse_focus_mask.clear_flag(mouse_button_to_mask(mb->get_button_index())); 
			if (!gui.mouse_focus) {
				
				return;
			}
			mb = mb->xformed_by(Transform2D()); 
			Point2 pos = gui.mouse_focus->get_global_transform_with_canvas().affine_inverse().xform(mpos);
			mb->set_position(pos);