Adjust configuration of the Rest5Client

[sothawo]

After the Elasticsearch client now provides additional callbacks (elastic/elasticsearch-java#1037), we need to integrate these into our configuration setup.

[sothawo]

related issue elastic/elasticsearch-java#1018, as of today (27.07.2025) not yet available in maven central

[l-trotta]

@sothawo sorry for just seeing this now, 9.0.4 has been released on the 18.07.2025, can't you see it here? There has been a change in the release pipeline since the OSSRH sunset, but in theory it shouldn't have affected releases.

[sothawo]

Hi, Laura,
I'm using mcs to search for libraries in maven, after upgrading mcs to the latest version I can see it now.