OpenSearch upgrade in data node for 6.2 release (validate new version!)

[mako42]

We should start testing the latest version of Open Search in time before the 6.2 release, as that will be our next opportunity to deliver a more recent version.
OpenSearch 2.19 is scheduled for end of January/middle of February (https://opensearch.org/releases.html), so we should decide whether that is enough time before GA to validate the version.
2.18 is already out and would be the alternative, we might have to start validating it anyways.

Version overview: