sagemathgh-38149: many pep8 fixes in misc

    
most of them scripted using `autopep8`, and a few ones by hand ; only in
`py` files

### 📝 Checklist

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
    
URL: sagemath#38149
Reported by: Frédéric Chapoton
Reviewer(s): David Coudert