deps: bump doxygen-awesome-css from 568f56c to af1d903

Bumps [doxygen-awesome-css](https://github.com/jothepro/doxygen-awesome-css) from `568f56c` to `af1d903`.
- [Release notes](https://github.com/jothepro/doxygen-awesome-css/releases)
- [Commits](jothepro/doxygen-awesome-css@568f56c...af1d903)

---
updated-dependencies:
- dependency-name: doxygen-awesome-css
  dependency-type: direct:production
...

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