[Fix](table size) Fix MoW table merge data fault (#40880)

Issue #40879 step 1

be/src/olap/rowset/rowset_meta.cpp

@@ -223,6 +223,7 @@ void RowsetMeta::merge_rowset_meta(const RowsetMeta& other) {
     set_num_segments(num_segments() + other.num_segments());
     set_num_rows(num_rows() + other.num_rows());
     set_data_disk_size(data_disk_size() + other.data_disk_size());
+    set_total_disk_size(total_disk_size() + other.total_disk_size());
     set_index_disk_size(index_disk_size() + other.index_disk_size());
     for (auto&& key_bound : other.get_segments_key_bounds()) {
         add_segment_key_bounds(key_bound);