chore: remove unused code (#17371)

Author: SkyFan2002

src/query/storages/fuse/src/statistics/block_statistics.rs

@@ -13,13 +13,11 @@
 // limitations under the License.
 
 pub mod accumulator;
-mod block_statistics;
 mod cluster_statistics;
 mod column_statistic;
 pub mod reducers;
 
 pub use accumulator::StatisticsAccumulator;
-pub use block_statistics::BlockStatistics;
 pub use cluster_statistics::sort_by_cluster_stats;
 pub use cluster_statistics::ClusterStatsGenerator;
 pub use column_statistic::calc_column_distinct_of_values;