Investigate whether we can avoid building all executables with Cabal-2.0

[mgsloan]

See #1406 and #3486 . Currently, all executables need to be built at least once, otherwise the copy step fails.

IIRC there were some PRs to cabal that were supposed to fix this issue. However, they didn't make it into <= Cabal-2.0. In theory, I think this should be fixed in Cabal-2.0. So we should:

• Check whether the logic to build all executables can be disabled when using Cabal-2.0 to do builds

• If not, file a ticket with the cabal issue tracker

[mgsloan]

Indeed, not fixed in Cabal-2.0, here is the issue: haskell/cabal#2780

[mgsloan]

Going to go ahead and close this, can be tracked by #3486