nix-serve: 0.2-e4675e3 -> unstable-2024-04-08

The current version in nixpkgs is from 2018, and there's been a lot of
fixes and features since then.

Passthru tests failed, as nix-serve seems to be shelling out to a
`nix-command` which needs an explicitly enabled since some Nix versions:

```
machine # [    5.920336] nix-serve-start[840]: error: experimental Nix feature 'nix-command' is disabled; use '--extra-experimental-features nix-command' to override
```

Rather than patching this, I fixed it by giving nix-serve a Nix binary
in $PATH that doesn't require that - while keeping the nix.perlBindings.

The passthru tests now succeed.

pkgs/tools/package-management/nix-serve/default.nix

@@ -3,24 +3,21 @@
 , fetchFromGitHub
 , bzip2
 , nix
+, nixVersions
 , perl
 , makeWrapper
 , nixosTests
 }:
 
-let
-  rev = "e4675e38ab54942e351c7686e40fabec822120b9";
-  sha256 = "1wm24p6pkxl1d7hrvf4ph6mwzawvqi22c60z9xzndn5xfyr4v0yr";
-in
-
 stdenv.mkDerivation {
   pname = "nix-serve";
-  version = "0.2-${lib.substring 0 7 rev}";
+  version = "0.2.0-unstable-2024-04-08";
 
   src = fetchFromGitHub {
     owner = "edolstra";
     repo = "nix-serve";
-    inherit rev sha256;
+    rev = "4a12660e6fa8fce662c0a652280a3309fa822465";
+    hash = "sha256-N7MK+m7hP34ALPy2tKgfPmz+uj/pkbh1Wq771BMHAfI=";
   };
 
   nativeBuildInputs = [ makeWrapper ];
@@ -31,8 +28,8 @@ stdenv.mkDerivation {
     install -Dm0755 nix-serve.psgi $out/libexec/nix-serve/nix-serve.psgi
 
     makeWrapper ${perl.withPackages(p: [ p.DBDSQLite p.Plack p.Starman nix.perl-bindings ])}/bin/starman $out/bin/nix-serve \
-                --prefix PATH : "${lib.makeBinPath [ bzip2 nix ]}" \
-                --add-flags $out/libexec/nix-serve/nix-serve.psgi
+      --prefix PATH : "${lib.makeBinPath [ bzip2 nixVersions.nix_2_3 ]}" \
+      --add-flags $out/libexec/nix-serve/nix-serve.psgi
   '';
 
   passthru.tests = {