chore: adjust row count assertion in table compaction (#15380)

fix: adjust row count assertion in table compaction

Correct the assertion to check that the row count remains unchanged
during table compaction, instead of comparing it(new snapshot) to the
pre-compaction snapshot. This change accounts for scenarios where the
new snapshot results from a combination of compaction and insertion,
potentially increasing the total number of rows.

Author: dantengsky

src/query/storages/fuse/src/operations/common/generators/mutation_generator.rs

@@ -110,10 +110,10 @@ impl SnapshotGenerator for MutationGenerator {
 
                     if matches!(self.mutation_kind, MutationKind::Compact) {
                         // for compaction, a basic but very important verification:
-                        // the number of rows should not be changed
+                        // the number of rows should be the same
                         assert_eq!(
-                            new_snapshot.summary.row_count,
-                            self.base_snapshot.summary.row_count
+                            ctx.merged_statistics.row_count,
+                            ctx.removed_statistics.row_count
                         );
                     }