Compress job traces
Problem to solve
Traces consume a LOT of space on the server. Unlike artifacts they never expire. Gitlab-CI usually prints much more information than code changes which have triggered it. So it may be the largest thing stored on our gitlab server (well, after registry which does not support proper delete, doh).
Size of traces on our instance is now 3 times higher than size of artifacts and the difference grows as most of artifacts are expiring. Projects with 100k+ builds have now 30-50G of traces, which is just too much. Job trace is plain text, which is the best file format to be compressed. Why not doing it?
Further details
Job artifacts model already has zip/gzip file format implemented, so it should be easy to implement.
Proposal
Implement trace compression and migration of raw trace to compressed trace.
What does success look like, and how can we measure that?
It would save 100's of GB of storage on our instance. Definitely TBs of storage on gitlab.com...
Links / references
This is spin-off from #49368 (moved)