Diff view shows all versions. E.g. if you enable/disable a script it
shows up in possible diff targets. This PR filters versiont to only show
the ones that have the field changed somehow.
refactor: clean up code to py39+ supported syntax
- f-strings instead of format
- latest typing support instead of pre 3.9 TitleCase
- remove UTF-8 declarations.
- many more changes
Powered by https://github.com/asottile/pyupgrade/ + manual cleanups
