Bump version to 6.17.0

• Diff: https://gitlab.com/gitlab-org/gitlab-qa/compare/v6.16.0...823ce929088c6e6ee20990a0e162b5bfe1c390d5

• Release notes:

### New scenarios and scenario updates

- !564 Modify root password for the ssh tunnel

### Other changes (CI, backstage)

- !618 Relate failures in the report stage
- !619 Disable ee:geo and ee:geo-quarantine jobs

• 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.