Bump version to 11.1.0

Diff

https://gitlab.com/gitlab-org/gitlab-qa/-/compare/v11.0.0...2903fd86b2fdf063df3b773bdeb3c78174097984

Checklist

• Diff link is up-to-date.
• Check the release notes: https://gitlab.com/api/v4/projects/gitlab-org%2Fgitlab-qa/repository/changelog?version=11.1.0
• Based on the diff and the release notes, version.rb is updated, according to SemVer.