### 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)

Control *over = nullptr;
		if (gui.mouse_in_viewport) {
			over = gui_find_control(mpos);
		}
		if (over != gui.mouse_over) {
			if (!gui.mouse_over) {
				_drop_physics_mouseover();
			}
			_drop_mouse_over();
			_gui_cancel_tooltip();
			if (over) {
				_gui_call_notification(over, Control::NOTIFICATION_MOUSE_ENTER);
				gui.mouse_over = over;
			}
		}
		if (gui.mouse_focus) {
			over = gui.mouse_focus;
		}
		DisplayServer::CursorShape ds_cursor_shape = (DisplayServer::CursorShape)Input::get_singleton()->get_default_cursor_shape();
		if (over) {
			Transform2D localizer = over->get_global_transform_with_canvas().affine_inverse();
			Size2 pos = localizer.xform(mpos);
			Vector2 velocity = localizer.basis_xform(mm->get_velocity());
			Vector2 rel = localizer.basis_xform(mm->get_relative());
			mm = mm->xformed_by(Transform2D()); 
			mm->set_global_position(mpos);
			mm->set_velocity(velocity);
			mm->set_relative(rel);
			if (mm->get_button_mask().is_empty()) {