Zenodo reverted their recent API changes, without communicating it - as far as I could observe.
We need to revert the API-changes-related part of #568.

Refs:

• Zenodo API link to files is probably invalid/incorrect zenodo/zenodo#2486
• KeyError: 'key' in ZenodoRepository.download_url() after Zenodo migration fatiando/pooch#371
• Fix bug: update Zenodo downloader for new API fatiando/pooch#373
• Fix bug: add support for old and new Zenodo APIs fatiando/pooch#375
• KeyError: 'size' when dowloading zenodo dataset dvolgyes/zenodo_get#19
• https://inveniordm.docs.cern.ch/reference/rest_api_drafts_records/#get-a-record