Bump webpack-merge from 4.2.2 to 5.0.9 (#14424)

Bump webpack-merge from 4.2.2 to 5.0.9 (#14424)

* Bump webpack-merge from 4.2.2 to 5.0.9

Bumps [webpack-merge](https://github.com/survivejs/webpack-merge) from 4.2.2 to 5.0.9.
- [Release notes](https://github.com/survivejs/webpack-merge/releases)
- [Changelog](https://github.com/survivejs/webpack-merge/blob/master/CHANGELOG.md)
- [Commits](https://github.com/survivejs/webpack-merge/compare/v4.2.2...v5.0.9)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Yamagishi Kazutoshi <ykzts@desire.sh>