- Rename the job in missing-commits.yml from "check" to "up_to_date",
because other jobs named "check" prevent merges, but this one should
not prevent merges. How else are branches going to get caught up?
- Move the job in instrumentation.yml to nix.yml, but keep it entirely
independent.
* Has more steps, but allows merges to develop to continue when a
beta / RC is pending, increasing developer velocity.
* Add a CI job to check that no reverse merges have been missed.
* Add some useful scripts in bin/git:
* Set up upstreams as expected for safer pushes
* Squash a bunch of branches
* Set the version number
