chore(deps-dev): bump webpack-merge from 4.2.1 to 4.2.2

Bumps [webpack-merge](https://github.com/survivejs/webpack-merge) from 4.2.1 to 4.2.2.
- [Release notes](https://github.com/survivejs/webpack-merge/releases)
- [Changelog](https://github.com/survivejs/webpack-merge/blob/master/CHANGELOG.md)
- [Commits](survivejs/webpack-merge@v4.2.1...v4.2.2)

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