Follow-up from "E2E: Generate knapsack report on scheduled runs"

The following discussions from !75479 (merged) should be addressed:

• @rymai started a discussion:

  question: WDYT of setting this variable in the .review:rules:start-review-app-pipeline rules definition: https://gitlab.com/gitlab-org/gitlab/-/blob/b5848df65207812b036487d4f2339f75d961f760/.gitlab/ci/rules.gitlab-ci.yml#L1570-1584. This can be done as a follow-up when we'll re-enable Review Apps on 2-hour schedules.

• @rymai started a discussion:

  Same here.