Patch for vector performance regression introduced by DDL DAG refactoring in seekdb

[wyfanxiao]

Description

This issue introduces a performance regression that also exists in the seekdb version and requires a patch.

Context

• Original Internal Work Item ID: 2025111100111889223

Creator: wyfanxiao

[hnwyllmm]

— The patch has been merged, including the changes for renew_single_snap_index.