### 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;
			}
		}
		gui.currently_dragged_subwindow = click_on_window;
		if (!click_on_window && gui.subwindow_focused) {
			
			_sub_window_grab_focus(nullptr);
		}
	}
	if (gui.subwindow_focused) {
		Ref<InputEventMouseMotion> mm = p_event;
		if (mm.is_valid()) {
			SubWindowResize resize = _sub_window_get_resize_margin(gui.subwindow_focused, mm->get_position());
			if (resize != SUB_WINDOW_RESIZE_DISABLED) {
				DisplayServer::CursorShape shapes[SUB_WINDOW_RESIZE_MAX] = {
					DisplayServer::CURSOR_ARROW,
					DisplayServer::CURSOR_FDIAGSIZE,
					DisplayServer::CURSOR_VSIZE,
					DisplayServer::CURSOR_BDIAGSIZE,
					DisplayServer::CURSOR_HSIZE,
					DisplayServer::CURSOR_HSIZE,
					DisplayServer::CURSOR_BDIAGSIZE,
					DisplayServer::CURSOR_VSIZE,
					DisplayServer::CURSOR_FDIAGSIZE
				};
				if (DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_CURSOR_SHAPE)) {
					DisplayServer::get_singleton()->cursor_set_shape(shapes[resize]);
				}
				return true; 
			}