Every CI lane rebuilds the world, which is where much of the runner time goes, and dependency resolution is repeated per job and per run. - Cache the Maven repository across jobs and runs. #15749 is a stale earlier attempt at this. - Share build output between jobs (a build stage plus artifact upload/download) instead of rebuilding per lane. Part of #19524.
Every CI lane rebuilds the world, which is where much of the runner time goes, and dependency resolution is repeated per job and per run.
Part of #19524.