mgr/dashboard: bump loader-utils in /src/pybind/mgr/dashboard/frontend

mgr/dashboard: bump loader-utils in /src/pybind/mgr/dashboard/frontend

Bumps [loader-utils](https://github.com/webpack/loader-utils) from 1.4.0 to 1.4.2.
- [Release notes](https://github.com/webpack/loader-utils/releases)
- [Changelog](https://github.com/webpack/loader-utils/blob/v1.4.2/CHANGELOG.md)
- [Commits](https://github.com/webpack/loader-utils/compare/v1.4.0...v1.4.2)

---
updated-dependencies:
- dependency-name: loader-utils
  dependency-type: indirect
...

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