InboundLanes: StorageDescriptor<
    [Key: FixedSizeBinary<4>],
    {
        last_confirmed_nonce: bigint;
        relayers: {
            messages: { begin: bigint; end: bigint };
            relayer: SS58String;
        }[];
        state: Enum<{ Closed: undefined; Opened: undefined }>;
    },
    true,
    never,
>

Map of lane id => inbound lane data.