Fluss support compatibility test

### Search before asking

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

### Motivation

Although Fluss claims backward compatibility between different versions—both for client-server interoperability and for ZooKeeper metadata and written data—these compatibility guarantees are currently not covered by any tests.
The purpose of this issue is to add tests that cover these scenarios.(Note: We may not need to add tests specifically for Fluss 0.6 and Fluss 0.7.)

### Solution

_No response_

### Anything else?

_No response_

### Willingness to contribute

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

The issue names no files or existing tests; start by locating the compatibility-test setup for client-server interoperability, ZooKeeper metadata, and written data. Define coverage for supported version pairs, excluding Fluss 0.6 and 0.7 if appropriate, and consider the work done when those compatibility scenarios run and pass.

Written by the indexing model from the issue text.