chore(deps): bump serialize-javascript and terser-webpack-plugin

Bumps [serialize-javascript](https://github.com/yahoo/serialize-javascript) and [terser-webpack-plugin](https://github.com/webpack-contrib/terser-webpack-plugin). These dependencies needed to be updated together.

Updates `serialize-javascript` from 1.9.1 to 4.0.0
- [Release notes](https://github.com/yahoo/serialize-javascript/releases)
- [Commits](yahoo/serialize-javascript@v1.9.1...v4.0.0)

Updates `terser-webpack-plugin` from 1.2.2 to 1.4.6
- [Release notes](https://github.com/webpack-contrib/terser-webpack-plugin/releases)
- [Changelog](https://github.com/webpack-contrib/terser-webpack-plugin/blob/v1.4.6/CHANGELOG.md)
- [Commits](webpack-contrib/terser-webpack-plugin@v1.2.2...v1.4.6)

---
updated-dependencies:
- dependency-name: serialize-javascript
  dependency-type: indirect
- dependency-name: terser-webpack-plugin
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>