CSV inclusion warning for Ruby 3.4.0

```
warning: /.../ruby/3.3.5/lib/ruby/3.3.0/csv.rb was loaded from the standard library, but will no longer be part of the default gems starting from Ruby 3.4.0.
You can add csv to your Gemfile or gemspec to silence this warning.
Also please contact the author of licensed-5.0.0 to request adding csv into its gemspec.
```

Please consider adding `csv` to the gemspec file.