Bump webpack-cli from 4.7.2 to 4.8.0 (#301)

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 4.7.2 to 4.8.0.
- [Release notes](https://github.com/webpack/webpack-cli/releases)
- [Changelog](https://github.com/webpack/webpack-cli/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack/webpack-cli/compare/[email protected]@4.8.0)

---
updated-dependencies:
- dependency-name: webpack-cli
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]