Bump webpack from 4.38.0 to 4.42.1

Bumps [webpack](https://github.com/webpack/webpack) from 4.38.0 to 4.42.1.
- [Release notes](https://github.com/webpack/webpack/releases)
- [Commits](webpack/webpack@v4.38.0...v4.42.1)

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