Allow all node.attr.* attributes for Data Node OpenSearch overrides

## What?

OpenSearch has allows arbitrary attributes configured via `node.attr.*` properties.

Our [current allow list](https://github.com/Graylog2/graylog2-server/blob/91150bd211f9dfe9e8e279054ce83915f29c78f4/data-node/src/main/java/org/graylog/datanode/opensearch/configuration/beans/impl/OpensearchConfigurationOverridesBean.java#L51-L57) is only allowlisting `node.attr.zone`.

Can this be expanded to `^node\\.attr\\..*$` ?

## Why?

Some features of OpenSearch, such as [Shard allocation filtering](https://docs.opensearch.org/latest/api-reference/index-apis/shard-allocation/) rely on node attributes. It is also common for OpenSearch administrators to define attributes that allow differentiating nodes.

## Your Environment

* OpenSearch Version: Data Node