Manual fourmolu override causes multiple problems

[maralorn]

I believe because of e04dd8f, my shell needs to compile 15 minutes on every nixpkgs bump. Also my installed fourmolu version in the shell does not format the same way that pre-commit-nix expects.

I am not sure what to do about this, as you probably don’t want to revert. But I wanted to note that this is causing me problems.

Possible solutions:

• Revert the change
• Ignore (I’ll probably override the package for me locally.)
• Change the fourmolu in nixpkgs to version 0.12. Holding it back on the stackage version is kinda pointless, because we need to build a newer version for hls anyway. (And honestly, the installed binary and hls should use the same fourmolu version, ideally.)

[sandydoo]

Fixed in #321.