gh-36921: various details in normaliz backend interface
    
just fixing some pep8 and ruff suggestions in the modified file

### 📝 Checklist

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
    
URL: #36921
Reported by: Frédéric Chapoton
Reviewer(s): Travis Scrimshaw

Author: Release Manager