Bump ejs and webpack-bundle-analyzer

Removes [ejs](https://github.com/mde/ejs). It's no longer used after updating ancestor dependency [webpack-bundle-analyzer](https://github.com/webpack-contrib/webpack-bundle-analyzer). These dependencies need to be updated together.


Removes `ejs`

Updates `webpack-bundle-analyzer` from 2.13.1 to 4.8.0
- [Release notes](https://github.com/webpack-contrib/webpack-bundle-analyzer/releases)
- [Changelog](https://github.com/webpack-contrib/webpack-bundle-analyzer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/webpack-bundle-analyzer/compare/v2.13.1...v4.8.0)

---
updated-dependencies:
- dependency-name: ejs
  dependency-type: indirect
- dependency-name: webpack-bundle-analyzer
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -39,7 +39,7 @@
     "postcss-loader": "^3.0.0",
     "sass-loader": "^7.1.0",
     "webpack": "^4.17.1",
-    "webpack-bundle-analyzer": "^2.13.1",
+    "webpack-bundle-analyzer": "^4.8.0",
     "webpack-cli": "^3.1.0",
     "workbox-webpack-plugin": "^3.4.1"
   },