build(deps): bump html5rdf from 1.2 to 1.2.1

Bumps [html5rdf](https://github.com/RDFLib/html5rdf) from 1.2 to 1.2.1.
- [Release notes](https://github.com/RDFLib/html5rdf/releases)
- [Changelog](https://github.com/RDFLib/html5rdf/blob/main/CHANGES.rst)
- [Commits](https://github.com/RDFLib/html5rdf/commits/v1.2.1)

---
updated-dependencies:
- dependency-name: html5rdf
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>