fix(storage): fix commit_epoch new_sst_id_number (#18438)

src/meta/src/hummock/manager/commit_epoch.rs

@@ -397,7 +397,7 @@ impl HummockManager {
                 }
             }
 
-            new_sst_id_number += group_table_ids.len();
+            new_sst_id_number += group_table_ids.len() * 2; // `split_sst` will split the SST into two parts and consumer 2 SST IDs
             sst_to_cg_vec.push((commit_sst, group_table_ids));
         }