dispose method
Implementation
@override
Future<void> dispose(GroupCallSession groupCall) async {
// only remove our own, to save requesting if we join again, yes the other side
// will send it anyway but welp
_encryptionKeysMap.remove(groupCall.localParticipant!);
_currentLocalKeyIndex = 0;
_latestLocalKeyIndex = 0;
_memberLeaveEncKeyRotateDebounceTimer?.cancel();
}