failed to get schema version, "There is no Write MVCC info for the schema version"

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

I use keyspace feature, (by setting keyspacename=xxx in the config file)

### 2. What did you expect to see? (Required)

No WARN log

### 3. What did you see instead (Required)

```
[2025/04/22 20:19:30.354 +08:00] [WARN] [domain.go:318] ["failed to get schema version"] [keyspaceName=ks1234] [error="There is no Write MVCC info for the schema version"] [version=63]
```

This WARN log indicates something wrong...
In domain package, we construct some MVCC key and get the mvcc data from tikv:
https://github.com/pingcap/tidb/blob/709bd1f95cd04823445531b77a629628d455f079/pkg/domain/domain.go#L449

I suspect this key does not consider the keyspace info, so the key is incorrect, and get no data.

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

master 7e32850b96fac9291818c5d942810b227e958c59