Bump optimize-css-assets-webpack-plugin from 5.0.1 to 6.0.1

Bumps [optimize-css-assets-webpack-plugin](https://github.com/NMFR/optimize-css-assets-webpack-plugin) from 5.0.1 to 6.0.1.
- [Release notes](https://github.com/NMFR/optimize-css-assets-webpack-plugin/releases)
- [Commits](NMFR/optimize-css-assets-webpack-plugin@v5.0.1...v6.0.1)

---
updated-dependencies:
- dependency-name: optimize-css-assets-webpack-plugin
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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