With the currently implementation of visibleTransitionsInProgress in possible that there is a scenario where you can have duplicate entries in the list and cause the wrong back stack entry to be composed.

This is because we first add all of the STARTED entries to the lists and then we add a LifecycleObserver than then re-adds entries when they go through ON_START.

While we could change the list to a MutableSet to avoid this, we would then lose the snapshot functionality of mutableStateListOf() and we want to still recompose in response to adding and removing entries from the list. So we should just treat the list like it is a set manually instead.