Delete gitlab-qa-report and related files

What does this MR do and why?

These tooling have been moved to https://gitlab.com/gitlab-org/ruby/gems/gitlab_quality-test_tooling now.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.