ec17e826 

Add `cabal check` to Haskell flake

Get some assurance that Hackage will accept a published package.
Time to Start Worker time Duration Time to finish
Config 0s 1s 1s 1s
Eval 1s 4s 4s 6s
Build 6s 2m33s 2m35s 2m41s
Suite 0s 2m39s 2m41s 2m41s