`onLoadRequested()` always released the `readyClickOperation` ongoing
operation, without checking whether it actually needs to/should (it
should only do so if the action initiating the operation was starting
the game by the host). This would crash all other consumers, who already
released the operation when their ready-up operation completed server
side.
To resolve, relax the constraint such that the operation can be ended
multiple times in any order. At the end of the day the thing that
matters is that the operation is done and the ready button is unblocked.
It needs to be explicitly stated that the users in this list are related
to the *joined* room. Especially since it's sharing its variable name
with `SpectatorStreamingClient` where it has the opposite meaning (is a
list of *globally* playing players).
