use new @mdn/browser-compat-data

[escattone]

Fixes #1425

Per mdn/browser-compat-data#6640, stop using deprecated mdn-browser-compat-data npm package and use the new @mdn/browser-compat-data package instead.

[peterbe]

I'm not entirely sure how to test this.
I did cd kumascript && git remote escattone ... && git checkout escattone/use-new.. && cd .. and then a full docker-compose pull.
But before I started, just make sure it's using these files and something from the image, I put in a console.log(...) in the kumascript/macros/Compat.ejs but it never prints anywhere in docker-compose up.
So I can't tell if it's using the local ./kumascript/ or if it's using the DockerHub image. Sigh.

But each individual line of change looks correct and very sane.
I guess we get a chance to try this again before we make a prod release. Just to be safe.

[escattone]

@peterbe Just FYI, I built and ran (via docker-compose) this kumascript image locally, double-checked that I could require("@mdn/browser-compat-data"), and then re-rendered a page with the compat macro. All of it was successful.