Make eslint rule an error instead of a warning
Make eslint rule an error instead of a warning

This will `@typescript-eslint/no-unused-vars` an error instead of a warning. It's helpful for the rule to error so that the build will fail so that you don't have to check the logs to see if there was a warning. See https://github.com/mrdoob/three.js/pull/20467 for context.
Liuer/three.js,makc/three.js.fork,gero3/three.js,greggman/three.js,jpweeks/three.js,fyoudine/three.js,kaisalmen/three.js,aardgoose/three.js,aardgoose/three.js,looeee/three.js,donmccurdy/three.js,makc/three.js.fork,06wj/three.js,WestLangley/three.js,Liuer/three.js,06wj/three.js,mrdoob/three.js,jpweeks/three.js,mrdoob/three.js,donmccurdy/three.js,fyoudine/three.js,kaisalmen/three.js,gero3/three.js,WestLangley/three.js,looeee/three.js,greggman/three.js