Remove eslin4b-prebuilt from dev deps

Author: marijnh

package.json

@@ -10,7 +10,6 @@
   "license": "MIT",
   "devDependencies": {
     "@codemirror/buildhelper": "^0.1.5",
-    "eslint4b-prebuilt": "^6.7.1",
     "esmoduleserve": "^0.2.0",
     "serve-static": "^1.14.1",
     "getdocs-ts": "^0.1.0",