[Fix](cloud-mow) Fix dup key problem due to calculating delete bitmaps for incremental rowsets based on wrong historical rowsets during SC (#49350)

### What problem does this PR solve?

When calculating delete bitmaps for incremental rowsets during schema
change double write phase, `sync_rowsets` on tmp_tablet may override
local converted historical rowsets with rowsets on new tablet. But these
rowsets will be removed when commit sc job.
This PR re-add converted rowsets after `sync_rowsets` to avoid the
problem

Author: bobhan1

be/src/cloud/cloud_schema_change_job.cpp

@@ -466,6 +466,10 @@ Status CloudSchemaChangeJob::_process_delete_bitmap(int64_t alter_version,
                 {start_calc_delete_bitmap_version, max_version}, &incremental_rowsets));
         DBUG_EXECUTE_IF("CloudSchemaChangeJob::_process_delete_bitmap.after.capture_without_lock",
                         DBUG_BLOCK);
+        {
+            std::unique_lock wlock(tmp_tablet->get_header_lock());
+            tmp_tablet->add_rowsets(_output_rowsets, true, wlock);
+        }
         for (auto rowset : incremental_rowsets) {
             RETURN_IF_ERROR(CloudTablet::update_delete_bitmap_without_lock(tmp_tablet, rowset));
         }