Bump webpack-dev-middleware, laravel-mix and webpack-dev-server

Bumps [webpack-dev-middleware](https://github.com/webpack/webpack-dev-middleware) to 7.1.1 and updates ancestor dependencies [webpack-dev-middleware](https://github.com/webpack/webpack-dev-middleware), [laravel-mix](https://github.com/JeffreyWay/laravel-mix) and [webpack-dev-server](https://github.com/webpack/webpack-dev-server). These dependencies need to be updated together.


Updates `webpack-dev-middleware` from 1.12.2 to 7.1.1
- [Release notes](https://github.com/webpack/webpack-dev-middleware/releases)
- [Changelog](https://github.com/webpack/webpack-dev-middleware/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-dev-middleware@v1.12.2...v7.1.1)

Updates `laravel-mix` from 2.1.14 to 6.0.49
- [Release notes](https://github.com/JeffreyWay/laravel-mix/releases)
- [Changelog](https://github.com/laravel-mix/laravel-mix/blob/master/CHANGELOG.md)
- [Upgrade guide](https://github.com/laravel-mix/laravel-mix/blob/master/UPGRADE.md)
- [Commits](https://github.com/JeffreyWay/laravel-mix/commits)

Updates `webpack-dev-server` from 3.7.2 to 5.0.4
- [Release notes](https://github.com/webpack/webpack-dev-server/releases)
- [Changelog](https://github.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-dev-server@v3.7.2...v5.0.4)

---
updated-dependencies:
- dependency-name: webpack-dev-middleware
  dependency-type: indirect
- dependency-name: laravel-mix
  dependency-type: direct:development
- dependency-name: webpack-dev-server
  dependency-type: direct:development
...

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

Author: dependabot[bot]