Settings for enabling reproducible builds for all subprojects were added to improve build consistency. This includes preserving file timestamps and ordering files reproducibly.
This is primarily of help for docker, since it uses hashes to determine if a file or image layer has changed.
... also move some common configuration into the root build.gradle-file.
Support for JDK21 in lombok is a bit sketchy at the moment, but it seems to work. This upgrade is kind of important as the new index construction really benefits from Arena based lifecycle control over off-heap memory.
This provides a much cleaner separation of concerns, and makes it possible to get rid of a lot of the gunkier parts of the index service. It will also permit lowering the Xmx on the index service a fair bit, so we can get CompressedOOps again :D
