Correcting invalid references to CompleteAsync() on TransactionScope in sample code

Transaction scope does not have an async version of Complete(). Changing code samples referencing CompleteAsync() to Complete().
Refer, https://docs.microsoft.com/en-us/dotnet/api/system.transactions.transactionscope?view=net-6.0

Author: Ausxor

articles/service-bus-messaging/service-bus-partitioning.md

@@ -68,7 +68,7 @@ using (TransactionScope ts = new TransactionScope(committableTransaction))
     ServiceBusMessage msg = new ServiceBusMessage("This is a message");
     msg.PartitionKey = "myPartitionKey";
     await sender.SendMessageAsync(msg); 
-    await ts.CompleteAsync();
+    await ts.Complete();
 }
 committableTransaction.Commit();
 ```
@@ -88,7 +88,7 @@ using (TransactionScope ts = new TransactionScope(committableTransaction))
     ServiceBusMessage msg = new ServiceBusMessage("This is a message");
     msg.SessionId = "mySession";
     await sender.SendMessageAsync(msg); 
-    await ts.CompleteAsync();
+    await ts.Complete();
 }
 committableTransaction.Commit();
 ```