(Flaky?) C++ test `CLUSTER_TEST`

As part of Python 3.9 cleanup, one of the C++ tests failed in [this CI job]( https://github.com/rapidsai/raft/actions/runs/10509784822/job/29119156426?pr=2417#step:7:705 )

```
The following tests FAILED:
	  1 - CLUSTER_TEST (Failed)
```

As this didn't happen in other jobs, this may be a flaky test

Raising here to track