Bump version to 7.34.0

• Diff: v7.33.0...9c5c4752

• Release notes:

### New scenarios and scenario updates

- !965 965 Start Gitaly cluster components in parallel to the GitLab container to improve boot time

• 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.