 CTL/purescriptFlake: error: nodejs_14 has been removed as it is EOL

Original: https://github.com/mlabs-haskell/lambda-buffers/issues/160

CTL uses older nixpkgs in which nodejs 14 is still not marked as dead.

I believe node2nix is the culprit here, but we should definitely fix CTL to have weekly and reliable nixpkgs upgrade as to not block its dependents.