Bump graphviz from 0.19.1 to 0.19.2
Bump graphviz from 0.19.1 to 0.19.2

Bumps [graphviz](https://github.com/xflr6/graphviz) from 0.19.1 to 0.19.2.
- [Release notes](https://github.com/xflr6/graphviz/releases)
- [Changelog](https://github.com/xflr6/graphviz/blob/master/CHANGES.rst)
- [Commits](https://github.com/xflr6/graphviz/compare/0.19.1...0.19.2)

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
annapowellsmith/openpresc,ebmdatalab/openprescribing,annapowellsmith/openpresc,ebmdatalab/openprescribing,annapowellsmith/openpresc,annapowellsmith/openpresc,ebmdatalab/openprescribing,ebmdatalab/openprescribing