Revert "Merge branch 'vanilla-mermaid' into 'master'"

What does this MR do and why?

Reverts changes made in !102199 (merged) for gitlab-com/gl-infra/production#7962 (closed).

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.