Welcome bot references zenodo but it was removed

[MegaByte]

Summary

The welcome bot configuration

qsiprep/.github/config.yml

Line 16 in a3b5eaa

[``.zenodo.json``](https://github.com/pennlinc/qsiprep/blob/master/.zenodo.json)

invites contributors to edit the .zenodo.json file, but this was replaced by CITATION.cff in #878