Cleanup / Optimize `maven_packages_spec.rb`
Summary
maven_packages_spec.rb
is in deep need of a cleanup.
See:
Improvements
- Use
let_it_be
vars - Use shared vars at the top of the file
- Review factories usage with https://test-prof.evilmartians.io/#/factory_prof
- Remove those AR queries to get maven XML files.
Risks
They are pretty low, at worst, the specs examples would not work anymore.