[Bug](partition) should not do reset for the partition_sorts (#49148)

### What problem does this PR solve?
Problem Summary:

the partition_sorts is unique_ptr，could release after destroy.
and when some extreme case like cancel, if source reset the sorter
early, the sink operator will coredump still use it.

be/src/pipeline/exec/partition_sort_source_operator.cpp

@@ -104,7 +104,6 @@ Status PartitionSortSourceOperatorX::get_sorted_block(RuntimeState* state,
     }
     if (current_eos) {
         // current sort have eos, so get next idx
-        local_state._shared_state->partition_sorts[local_state._sort_idx].reset(nullptr);
         local_state._sort_idx++;
     }