Update version 8.0.0

• Diff: v7.36.0...0d8b80ed

• Release notes:

Fixes

• Remove colour decorations from debug log file (!995 - merged)

Docs

• Update run_qa_against_gdk.md (!987 - merged)

Other changes (CI, backstage)

• Add Zeitwerk code loader (!996 - merged)
• Default to Elasticsearch 8.2.0 (!994 - merged)

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.