Move away from legacy OSSRH API for publishing

[alecgrieser]

For publishing to maven central, we are currently going through the legacy OSSRH compatibility API (via the nexus plugin). This allowed us to use the old system we'd set up when the old maven central publishing portal was sunset. There is a new API to use, though, and we should switch over to it.

There was a recent build failure that this may be related to: https://github.com/FoundationDB/fdb-record-layer/actions/runs/18949783608/job/54123274986

> Task :closeSonatypeStagingRepository FAILED

[Incubating] Problems report is available at: file:///home/runner/work/fdb-record-layer/fdb-record-layer/.out/reports/problems/problems-report.html

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':closeSonatypeStagingRepository'.
> Failed to close staging repository, server at https://ossrh-staging-api.central.sonatype.com/service/local/ responded with status code 400, body: Failed to process request: No objects found in the repository

The error message indicates that the uploading/publishing failed, as it thinks that it wasn't able to upload the artifacts, even though when I checked the portal via the web, everything was there. I didn't see other people with this issue, but it is plausible that this could be related to using the legacy tech. It would be good to upgrade to at least rule that out.

[alecgrieser]

We had to revert this due to memory issues with JReleaser (see #3721).