GitLab CE artifacts passing

In GitLab CE we use artifacts passing from prepare to test. We generate there an archive that weights 60MB. This given amplification effect leads to the fact that we then generate 60MB*~40 builds traffic for each commit.

I think that we should think about optimizing that by:

1. Reducing the size of artifacts,
2. Building in-cache-based artifacts passing (in GitLab CI).

@stanhu @pcarranza @rymai To make you aware of the potential egress cost of having it like that.