Bump webpack from 4.38.0 to 4.39.0 ( Bumps [webpack](https://github.com/webpack/webpack) from 4.38.0 to 4.39.0. - [Release notes](https://github.com/webpack/webpack/releases) - [Commits](https://github.com/webpack/webpack/compare/v4.38.0...v4.39.0) Signed-off-by: dependabot-preview[bot]