Cleanup 3

Author: GrigoriyPA

ydb/library/yql/dq/runtime/dq_arrow_helpers.cpp

@@ -1008,8 +1008,8 @@ class TBlockSplitter : public IBlockSplitter {
             std::vector<arrow::Datum> backData = Data;
             for (ui64 i : ArraysIdx) {
                 const auto& array = *Data[i].array();
-                Data[i] = arrow::Datum(array.Slice(0, offset));
-                backData[i] = arrow::Datum(array.Slice(offset, length));
+                Data[i] = array.Slice(0, offset);
+                backData[i] = array.Slice(offset, length);
             }
 
             NumberRows -= length;