Bump dompurify from 2.4.4 to 2.5.4 in /src/headless

Bumps [dompurify](https://github.com/cure53/DOMPurify) from 2.4.4 to 2.5.4.
- [Release notes](https://github.com/cure53/DOMPurify/releases)
- [Commits](https://github.com/cure53/DOMPurify/compare/2.4.4...2.5.4)

---
updated-dependencies:
- dependency-name: dompurify
  dependency-type: direct:production
...

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