Fix nixpkgs ghc96

[hellwolf]

Description

To fix the upstream nixpkgs, I took few hours to tackle couple of issues I encountered.

I realized #471 is ongoing. So this may be duplicate work, partially.

What I did:

1. I did want to see if I could make cabal --allow-newer --enable-tests --enable-bench build all work. In doing so, I was guided by -Wunused-packages option to remove bunch of red-herring dependency issues.
2. I fixed build errors due to newer packages or ghc 9.6, some already present in Update GHC to 9.6 #471
   • I did not use the test suite thoroughly, since I am not familiar with hevm test suite.
3. update nixpkgs flake input.

Checklist

• tested locally
• added automated tests
• updated the docs
• updated the changelog

[msooseth]

Hi! #471 has been merged. Do you think there are things that would be of interest to port? For example the red herring dependencies you found? Let me know what you think,

Mate

[hellwolf]

Hi, I would really like to clean up the cabal file free of unused dependencies! I will work on this and send a patch.

[msooseth]

NICE. Thanks a lot! Looking forward :)

[hellwolf]

@msooseth #518