cabal2nix: Fix for justStaticExecutables

Remove references to `hpack` and `distribution-nixpkgs` paths so that
`cabal2nix` can build on macOS.

See: #304352

pkgs/development/haskell-modules/configuration-darwin.nix

@@ -335,6 +335,15 @@ self: super: ({
 
 } // lib.optionalAttrs pkgs.stdenv.isAarch64 { # aarch64-darwin
 
+ cabal2nix = overrideCabal (old: {
+ postInstall = ''
+ ${old.postInstall or ""}
+ remove-references-to -t ${self.hpack} "$out/bin/cabal2nix"
+ # Note: The `data` output is needed at runtime.
+ remove-references-to -t ${self.distribution-nixpkgs.out} "$out/bin/hackage2nix"
+ '';
+ }) super.cabal2nix;
+
  # https://github.com/fpco/unliftio/issues/87
  unliftio = dontCheck super.unliftio;
  # This is the same issue as above; the rio tests call functions in unliftio