Function dispatch_version_verification 

fn dispatch_version_verification(
    tx: &Transaction,
    nu: NetworkUpgrade,
    script_verifier: Verifier,
    cached_ffi_transaction: Arc<CachedFfiTransaction>,
) -> Result<AsyncChecks, TransactionError>

Dispatches version-specific async verification checks for tx.

nu is the network upgrade active at the transaction’s verification height, pre-computed by the caller using NetworkUpgrade::current.

Returns TransactionError::WrongVersion for V1-V3 transactions, which are not supported by any network upgrade Zebra verifies.