Bump oxigraph from 0.5.8 to 0.5.9 in /rust/case2geojson

Bumps [oxigraph](https://github.com/oxigraph/oxigraph) from 0.5.8 to 0.5.9.
- [Release notes](https://github.com/oxigraph/oxigraph/releases)
- [Changelog](https://github.com/oxigraph/oxigraph/blob/v0.5.9/CHANGELOG.md)
- [Commits](oxigraph/oxigraph@v0.5.8...v0.5.9)

---
updated-dependencies:
- dependency-name: oxigraph
  dependency-version: 0.5.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]