Upgrade mermaid-js to v8.13.2

What does this MR do and why?

This fixes a number of issues and introduces some cool new diagrams, such as Git graph and user journey diagrams: https://github.com/mermaid-js/mermaid/releases

Screenshots or screen recordings

How to set up and validate locally

Use this branch. In an issue, add a mermaid block:

gitGraph:
options
{
    "nodeSpacing": 150,
    "nodeRadius": 10
}
end
commit
branch newbranch
checkout newbranch
commit
commit
checkout master
commit
commit
merge newbranch

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.