npm: bump @rdfjs-elements/formats-pretty in /asctb-api

Bumps [@rdfjs-elements/formats-pretty](https://github.com/zazuko/rdfjs-elements/tree/HEAD/packages/formats) from 0.3.4 to 0.6.4.
- [Release notes](https://github.com/zazuko/rdfjs-elements/releases)
- [Changelog](https://github.com/zazuko/rdfjs-elements/blob/master/packages/formats/CHANGELOG.md)
- [Commits](https://github.com/zazuko/rdfjs-elements/commits/@rdfjs-elements/[email protected]/packages/formats)

---
updated-dependencies:
- dependency-name: "@rdfjs-elements/formats-pretty"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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