Function deactivate_touch_pointers

pub fn deactivate_touch_pointers(
    commands: Commands<'_, '_>,
    despawn_list: Local<'_, HashSet<(Entity, PointerId)>>,
    pointers: Query<'_, '_, (Entity, &PointerId)>,
    touches: EventReader<'_, '_, TouchInput>,
)

Deactivates unused touch pointers.

Because each new touch gets assigned a new ID, we need to remove the pointers associated with touches that are no longer active.