Implement process to update knapsack files for QA pipelines

The following discussion from !14755 (merged) should be addressed:

• @rymai started a discussion: (+1 comment)

  What's the plan around updating these files? Something like a bi-weekly manual update maybe?

One option is to use the {retrieve|update}-tests-metadata jobs to automate it.

A better option might be to use artifacts, as proposed here: omnibus-gitlab#4519 (moved)