[Bug] when recovery from state，the LabelGenerator generateTableLabel maybe generate repeat label

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/incubator-doris/issues?q=is%3Aissue) and found no similar issues.

### Version

25.1.0-SNAPSHOT

### What's Wrong?

org.apache.doris.flink.exception.DorisRuntimeException：
stream load error: [LABEL_ALREADY_EXISTS]errCode = 2, detailMessage = Label[labelprefix_db1_table1_1_0] has already been used, relate
to txn [38597], see more in null at org.apache.doris.flink.sink.writer.DorisWriter. prepareCommit(DorisWriter.java:

### What You Expected?

no error

### How to Reproduce?

_No response_

### Anything Else?

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

Start by reading LabelGenerator and the prepareCommit path in DorisWriter.java, focusing on recovery from state and the reported LABEL_ALREADY_EXISTS error. Reproduce the state-recovery scenario if possible and verify that generated labels do not repeat before considering the issue complete.

Written by the indexing model from the issue text.