[npm] Bump @mui/styled-engine-sc in /frontend

Bumps [@mui/styled-engine-sc](https://github.com/mui/material-ui/tree/HEAD/packages/mui-styled-engine-sc) from 6.0.0-alpha.12 to 6.0.0-alpha.14.
- [Release notes](https://github.com/mui/material-ui/releases)
- [Changelog](https://github.com/mui/material-ui/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mui/material-ui/commits/HEAD/packages/mui-styled-engine-sc)

---
updated-dependencies:
- dependency-name: "@mui/styled-engine-sc"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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