BR Restore progress value exceeds 100%.on TiDB Cloud

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

1. start a v9.0.0 cluster on tidb cloud
2. prepare tpcc data
3. do backup on tidb cloud
4. restore backup
5. during restore procedure, the progress value start with 100%, then 112%, then 100%.

### 2. What did you expect to see? (Required)
Accurate progress value gradually increasing to 100%

### 3. What did you see instead (Required)
112% in progress

### 4. What is your TiDB version? (Required)

Release Version: v9.0.0-beta.1
Edition: Enterprise
Git Commit Hash: 7b4717bf180ec94d5d42dc4d5ca3711d34131370
Git Branch: HEAD
UTC Build Time: 2025-03-13 03:08:16
GoVersion: go1.23.7
Race Enabled: false
Check Table Before Drop: false
Store: tikv
Enterprise Extension Commit Hash: dc633aae52eb11b4e3549e3a7ef5b0ed14e159b1