Bump ejs and webpack-bundle-analyzer in /old page/sources

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 4.6.1
- [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](webpack/webpack-bundle-analyzer@v2.13.1...v4.6.1)

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

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

old page/sources/package.json

@@ -75,7 +75,7 @@
     "vue-style-loader": "^3.1.2",
     "vue-template-compiler": "^2.5.17",
     "webpack": "^3.12.0",
-    "webpack-bundle-analyzer": "^2.13.1",
+    "webpack-bundle-analyzer": "^4.6.1",
     "webpack-dev-server": "^2.11.5",
     "webpack-merge": "^4.1.4"
   },