go/runtime/txpool: Remove workaround for future txs bug

Author: peternose

.changelog/6394.trivial.md

@@ -588,21 +588,9 @@ func (t *txPool) checkTxBatch(ctx context.Context) error {
 	)
 
 	// Queue checked transactions for scheduling.
-	stateSeqNums := make(map[string]uint64)
 	for i, pct := range goodPcts {
 		idx := batchIndices[i]
 		res := results[idx]
-
-		// XXXX: Temporary workaround for an Oasis SDK bug that incorrectly
-		// increments the sender's state sequence number during transaction
-		// check.
-		sender := string(res.Meta.Sender)
-		if seq, ok := stateSeqNums[sender]; ok {
-			res.Meta.SenderStateSeq = seq
-		} else {
-			stateSeqNums[sender] = res.Meta.SenderStateSeq
-		}
-
 		if err = t.mainQueue.Add(pct.TxQueueMeta, res.Meta); err != nil {
 			t.logger.Error("unable to queue transaction for scheduling",
 				"err", err,