Feature: add testing for the installer including Jenkins part.

our current GH action does testing different disto on different jdk release, but the missing part is:
1. gpg signing
2. jenkins pipeline (mostly of the changes we made for jenkinsfile)

This issue is to catch these two missing points, and find a good way so we do not slip bug during release.
or at least in the dry-run before release, we can do some installer build (with previous release binary + no upload to artifactory)

Start by reviewing the current GitHub Action and the Jenkinsfile changes mentioned in the issue, then compare which installer paths are covered. Define a dry-run release check that exercises GPG signing and installer builds with a previous release binary without uploading to Artifactory; done means both missing areas are tested before release.

Written by the indexing model from the issue text.