Add LongRunning option to managed SNI async reads (#19739)

Author: corivera

src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNIPacket.cs

@@ -267,7 +267,7 @@ public void ReadFromStreamAsync(Stream stream, SNIAsyncCallback callback)
                 callback(this, error ? TdsEnums.SNI_ERROR : TdsEnums.SNI_SUCCESS);
             },
             CancellationToken.None,
-            TaskContinuationOptions.DenyChildAttach,
+            TaskContinuationOptions.DenyChildAttach | TaskContinuationOptions.LongRunning,
             TaskScheduler.Default);
         }