bug#51837: [Cuirass] Wrong type: #f in cuirass/templates.scm

[John Kehayias via Bug reports for GNU Guix]

I've noticed not getting build detail pages for in-progress or scheduled 
builds. I definitely noticed in the last few days with trying to see the builds 
with the core-updates-frozen-batched-changes merge (there was a long gc job 
forceably killed, maybe other wonkiness?). But I can't be sure if it was before 
that as well.