The signing key expired some time ago, and while I made a
new signing key, there's no indication that a different
key is being used. Update the ID for future signatures.
This is the start of a release script. The idea is to automate
a whole bunch of the steps documented in ci/RELEASE.md, so that
a release becomes more straightforward. Assumptions abound:
basically this is going to work on my workstation, and not
on any other.