Shirly

summary for this issue: ### Split and transfer-region-leader applied to the same region simultaneously causes region not found for key [tikv#17602](https://github.com/tikv/tikv/issues/17602) [tikv#12410](https://github.com/tikv/tikv/issues/12410) - Phenomenon: TiDB logs report `region not found...

> And the request might be affected by the backoff because we need to wait for the stream to be re-established. I think this should meet expectations, if not waiting...

Here is my question, why we do not reuse the old store object directly instead of create a new one? https://github.com/tikv/client-go/blob/01758810e8419b784c0b652ad32ef03664df50bd/internal/locate/store_cache.go#L494-L521