Use 1 knapsack report for both distributions

What does this MR do?

Uses a knapsack master report file that includes all tests (for CE and EE) when testing both distributions.

This allows the omnibus upgrade scenario to be parallelized (it tests CE first, then EE, so it wouldn't work when the QA image was missing one of the separate report files)

Required by:

• https://gitlab.com/gitlab-org/quality/nightly/merge_requests/40
• gitlab-qa!284 (merged)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content