[test] Unstable test TableManagerITCase.testSchemaEvolution

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/fluss/issues) and found nothing similar.

### Fluss version

main (development)

### Please describe the bug 🐞

https://github.com/apache/fluss/actions/runs/24082097729/job/70254755988?pr=3000

```
Error: Tests run: 19, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 48.878 s <<< FAILURE! - in org.apache.fluss.server.coordinator.TableManagerITCase
Error: org.apache.fluss.server.coordinator.TableManagerITCase.testSchemaEvolution Time elapsed: 2.163 s <<< FAILURE!
org.opentest4j.AssertionFailedError:

expected: 2
but was: 1
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at org.apache.fluss.server.coordinator.TableManagerITCase.testSchemaEvolution(TableManagerITCase.java:709)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:727)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
```

### Solution

_No response_

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Start with org.apache.fluss.server.coordinator.TableManagerITCase.testSchemaEvolution, especially the assertion at line 709, and review the linked CI failure. Run this integration test repeatedly to determine why schema evolution sometimes produces 1 instead of the expected 2. Done means the test is reliable and passes with the expected result.

Written by the indexing model from the issue text.