Ensure changelog filenames have length less than 99 characters

What does this MR do?

docker-api gem in omnibus-gitlab uses tar under the hood, which as a maximum limit of 99 characters on file names. So, let us limit the changelog filenames to 99 characters.

Conformity

• Changelog entry for user-facing changes, or community contribution. Check the link for other scenarios.
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content