### 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;
		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
			if (!get_tree()) {
				return;
			}
			if (get_tree()->is_debugging_collisions_hint() && contact_2d_debug.is_valid()) {
				RenderingServer::get_singleton()->canvas_item_clear(contact_2d_debug);
				RenderingServer::get_singleton()->canvas_item_set_draw_index(contact_2d_debug, 0xFFFFF); 
				Vector<Vector2> points = PhysicsServer2D::get_singleton()->space_get_contacts(find_world_2d()->get_space());
				int point_count = PhysicsServer2D::get_singleton()->space_get_contact_count(find_world_2d()->get_space());
				Color ccol = get_tree()->get_debug_collision_contact_color();
				for (int i = 0; i < point_count; i++) {
					RenderingServer::get_singleton()->canvas_item_add_rect(contact_2d_debug, Rect2(points[i] - Vector2(2, 2), Vector2(5, 5)), ccol);
				}
			}
#ifndef _3D_DISABLED
			if (get_tree()->is_debugging_collisions_hint() && contact_3d_debug_multimesh.is_valid()) {
				Vector<Vector3> points = PhysicsServer3D::get_singleton()->space_get_contacts(find_world_3d()->get_space());
				int point_count = PhysicsServer3D::get_singleton()->space_get_contact_count(find_world_3d()->get_space());
				RS::get_singleton()->multimesh_set_visible_instances(contact_3d_debug_multimesh, point_count);
				for (int i = 0; i < point_count; i++) {
					Transform3D point_transform;
					point_transform.origin = points[i];
					RS::get_singleton()->multimesh_instance_set_transform(contact_3d_debug_multimesh, i, point_transform);
				}
			}
#endif 
		} break;
		case NOTIFICATION_VP_MOUSE_ENTER: {
			gui.mouse_in_viewport = true;