statistics: test `tidb_partition_prune_mode` session variable (#23176)
statistics: test `tidb_partition_prune_mode` session variable (#23176)


kyle-wang/tidb,c4pt0r/tidb,kyle-wang/tidb,pingcap/tidb,c4pt0r/tidb,kyle-wang/tidb,coocood/tidb,kyle-wang/tidb,c4pt0r/tidb,ngaut/tidb,ngaut/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb,c4pt0r/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb,kyle-wang/tidb,ngaut/tidb,c4pt0r/tidb,ngaut/tidb,coocood/tidb,pingcap/tidb,kyle-wang/tidb,c4pt0r/tidb