Bump reffy from 20.0.1 to 20.0.2

Bumps [reffy](https://github.com/w3c/reffy) from 20.0.1 to 20.0.2.
- [Changelog](https://github.com/w3c/reffy/blob/main/CHANGELOG.md)
- [Commits](https://github.com/w3c/reffy/commits)

---
updated-dependencies:
- dependency-name: reffy
  dependency-version: 20.0.2
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]