Fix latest version to be incremental

What does this MR do?

Fix CHANGELOG to have versions be incremental.

What are the relevant issue numbers?

gitlab-org/gitlab#11797 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added
• [-] Documentation created/updated for GitLab EE, if necessary
• [-] Documentation created/updated for this project, if necessary
• [-] Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• [-] Job definition updated, if necessary
• [-] Auto-DevOps template
• [-] Job definition example
• [-] CI Templates
• [-] Conforms to the code review guidelines
• [-] Conforms to the Go guidelines
• [-] Security reports checked/validated by reviewer