chore(deps-dev): bump webpack in /build/frontend-legacy

Bumps [webpack](https://github.com/webpack/webpack) from 5.106.2 to 5.108.4.
- [Release notes](https://github.com/webpack/webpack/releases)
- [Changelog](https://github.com/webpack/webpack/blob/main/CHANGELOG.md)
- [Commits](webpack/webpack@v5.106.2...v5.108.4)

---
updated-dependencies:
- dependency-name: webpack
  dependency-version: 5.108.4
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]