Author/editor responsibility for Zenodo upload + codecheck.yml update

This is possibly biased by my [ReScience C](https://rescience.github.io/) experience, but wouldn't it make sense to have the final steps that formalize the CODECHECK, i.e. the upload to Zenodo and the update of the `codecheck.yml` to be rather an editor and not a reviewer task? If I am not mistaken, so far @sje30 and @nuest have been both editors and reviewers at the same time, so this question did not really arise yet. In my opinion, having these final "validation" tasks been done by editors could avoid incorrect (in the sense of missing files, metadata, etc.) code checks being uploaded to Zenodo and in general ensure consistency. I could also imagine that in the future you might decide to e.g. have additional metadata in the Zenodo deposit – it would be easier if you could add them yourself instead of asking reviewers to do it. Of course, ideally you'd have a bot like JOSS's [whedon](https://joss.readthedocs.io/en/latest/whedon.html) do these tasks for you :)

Review the discussion in issue #21, focusing on the proposed division of responsibility for the Zenodo upload and the codecheck.yml update. Before implementation, establish whether editors should own these final validation steps, what metadata and files must be checked, and whether automation is in scope; done means the workflow is decided and documented.

Written by the indexing model from the issue text.