Update release process

[juherr]

See https://central.sonatype.org/news/20250326_ossrh_sunset/

The OSSRH service will reach end-of-life on June 30th, 2025. This coincides with the end-of-life date of the underlying technology, Sonatype's Nexus Repository Manager v2.

The release to Central has to use the new API.

I see the following options:
a) Replace stage-vote-release with com.gradleup.nmcp (or an alternative) Gradle Plugin to publish to Central Portal
b) Use jreleaser or an alternative

Just in case, I'm the author and the sole maintainer of stage-vote-release-plugin, and I advice you to stop using it. Sonatype drops the old API, and I find no reasons to support "Central Portal" in stage-vote-release-plugin.
It turns so that 90% of stage-vote-release features are related to "Apache Software Foundation" requirements like "publish release artifacts to svn, publish preview site, publish git tag", and they look like an excessive overhead for typical GitHub-based open-source software. I am afraid it might be hard to support Gradle Configuration Cache in stage-vote-release-plugin, it could be one more reason to stop using it.

Based on my research, I settled on com.gradleup.nmcp (it has recent releases, it has minimal set of features) which is currently maintained by @martinbonnin. There are some edge cases, and there's no 1.0.0 yet, however it requires only a minimal configuration, and it just works.

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I've switched a couple of my recent projects to GitHub release workflow + nmcp for publishing to Central + release-drafter for GitHub releases and git tags, and I like the results:

• https://github.com/burrunan/gradle-s3-build-cache/releases
• https://github.com/vlsi/vlsi-release-plugins/releases

I could help with making the needed changes.

I'm currently migrating pgjdbc release workflow to nmcp:

• chore: migrate publish workflow to Central Portal publishing via com.gradleup.nmcp pgjdbc/pgjdbc#3686

It is up to you to decide, however, I'm not a fan of jreleaser, so I can't comment there.

Originally posted by @vlsi in #2812

[juherr]

@vlsi Do you hava some free time to update the release process of TestNG?

@krmahadevan fyi