Sync bot crushing partial reviews

Hi @iliakan

I discovered this in the Spanish repo,
but happens in the other repos too.
...

Previously, the bot used different branches for sync, closing the old PR and generating a new one over a new branch. Partial reviews were preserved in the closed PR.

Now, the bot closes the old PR but always uses the same branch, doing a force push on it that destroys any partial reviews.

未指定文件、测试或入口点。首先定位 sync bot 对分支和 pull request 的处理，然后复现一次包含部分 review 的同步；当同步不再通过 force-push 覆盖已 review 的工作并保留 review 上下文时，即视为完成。