RKE2 Deployment Fails, Can't connect to Datanode

## Summary
org.graylog2.configuration.IndexerDiscoveryProvider - No datanode is available. Retry #1

### Details
All containers are in the same namespace

From the datanode logs, it appears that the opensearch cluster is never created.
`[ClusterNodeStateTracer] Updating cluster node 08a99607-8fc6-4a7a-b5b2-55d6ad6d1fd9 from UNAVAILABLE to UNAVAILABLE (reason: PROCESS_TERMINATED)`

There are also `Interrupted operation as its client disconnected` errors in the mongodb logs but these may be a result of the graylog nodes not completing setup since they cannot reach datanodes.

### Impact
Graylog cluster never completes deployment. Graylog nodes stuck "In Progress" perpetually.

## How to Reproduce?
kubectl delete -f namespace
kubecstl apply -f release

## Environment

- Helm chart version: 1.0.0
- Graylog version: 7.1.3
- Kubernetes version: v1.34.6+rke2r3
- Cloud provider / platform: RKE2 On Prem
- StorageClass: nfs-subdir-external-provisioner