Bump VERSION to 4.10.0

• Diff: v4.9.0...c9bf9576

• Release notes:

### New scenarios and scenario updates

- !311 Add a scenario to test Praefect

### Other changes (CI, backstage)

- !324 Add logs for vars passed from upstream

• 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:

  • Create a tag for the new release version.