Update version 8.0.0

• Diff: https://gitlab.com/gitlab-org/gitlab-qa/-/compare/v7.36.0...0d8b80ed0ef08321abf4b942fd0d717a9da67ca6

• Release notes:

Fixes

• https://gitlab.com/gitlab-org/gitlab-qa/-/merge_requests/995+

Docs

• https://gitlab.com/gitlab-org/gitlab-qa/-/merge_requests/987+

Other changes (CI, backstage)

• https://gitlab.com/gitlab-org/gitlab-qa/-/merge_requests/996+
• https://gitlab.com/gitlab-org/gitlab-qa/-/merge_requests/994+

Checklist before merging

• Diff link is up-to-date.
• Based on the diff, lib/gitlab/qa/version.rb is updated, according to SemVer.
• Release notes are accurate.

Checklist after merging

• Update the release notes for the newly created tag.