Bump VERSION to 5.0.1

• Diff: v5.0.0...ce851a92

• Release notes:

### Fixes

- !401 Include bundler/setup in exe/gitlab-qa-report

### Other changes (CI, backstage)

- !401 Report master pipeline test results in issues

• 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.