Bump webpack from 4.29.4 to 4.29.6

Bumps [webpack](https://github.com/webpack/webpack) from 4.29.4 to 4.29.6.
- [Release notes](https://github.com/webpack/webpack/releases)
- [Commits](https://github.com/webpack/webpack/compare/v4.29.4...v4.29.6

)

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