Draft: POC for archiving old pipelines

What does this MR do and why?

This is a POC for the idea described in &11815 (comment 1800830581)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

We have one directory for each pipeline containing the attributes and relations as an archive and a directory for artifacts:

Each artifact has its own directory in the pipeline to avoid collisions:

Archive structure:

marius@rocket-sled ~/W/g/gitlab (mb-archive-pipeline-poc)> tar -tf ~/Downloads/9489_100.tar.gz
./
./pipeline/
./pipeline.json
./pipeline/builds.ndjson
./pipeline/job_artifacts.ndjson

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.