chore(deps-dev): Bump workbox-webpack-plugin in /build/frontend-legacy

Bumps [workbox-webpack-plugin](https://github.com/googlechrome/workbox) from 7.4.0 to 7.4.1.
- [Release notes](https://github.com/googlechrome/workbox/releases)
- [Commits](GoogleChrome/workbox@v7.4.0...v7.4.1)

---
updated-dependencies:
- dependency-name: workbox-webpack-plugin
  dependency-version: 7.4.1
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]