Support Flink 1.18 compatible for remove_orphan_files action

### Search before asking

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

### Description

PR #3404 introduces the `remove_orphan_files` action for cleaning orphan files in remote storage. The current implementation adds compatibility and test coverage for newer Flink versions, but it does not fully support Flink 1.18 yet.

In particular, the action should be available and runnable from the Flink 1.18 module in the same way as the supported newer Flink versions.

## Expected behavior

`remove_orphan_files` should work with Flink 1.18, including:

- registering the action factory in the Flink 1.18 module
- compiling against the Flink 1.18 APIs
- running the orphan files cleanup action successfully with Flink 1.18
- adding Flink 1.18-specific IT coverage, similar to the existing coverage for newer Flink versions

## Related work

- #3404

## Test Plan

Add and run Flink 1.18 coverage for the orphan files cleanup action, for example:

- `Flink118OrphanFilesCleanITCase`
- relevant `fluss-flink-1.18` module tests

### Willingness to contribute

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

Start with PR #3404 and the existing newer-version implementation, then inspect the fluss-flink-1.18 module and its action factory registration. Use Flink118OrphanFilesCleanITCase and related module tests as the reference; done means the module compiles against Flink 1.18 and the orphan-files cleanup action runs successfully with equivalent integration coverage.

Written by the indexing model from the issue text.