Other(refactor): Sort safe.Mutex types before locking to prevent deadlocks

This change implements safe.Mutex and safe.RWMutex, which wrap the
sync.Mutex and sync.RWMutex types and are assigned a globally unique
integer ID. The safe.Lock and safe.RLock methods sort the mutexes
by this integer ID before locking to ensure that locks for a given
set of mutexes are always performed in the same order, avoiding
deadlocks.

internal/bridge/user_events.go

@@ -49,7 +49,7 @@ func (bridge *Bridge) handleUserEvent(ctx context.Context, user *user.User, even
 			defer delete(bridge.users, user.ID())
 
 			bridge.logoutUser(ctx, user, false)
-		}, &bridge.usersLock)
+		}, bridge.usersLock)
 	}
 
 	return nil