ocamlPackages.luv: clean up ocaml version handling

OCaml 4.08 and below has been removed from nix so we can assume we have
at least 4.09.

pkgs/development/ocaml-modules/luv/default.nix

@@ -1,7 +1,6 @@
 {
   lib,
   buildDunePackage,
-  ocaml,
   fetchurl,
   ctypes,
   result,
@@ -19,8 +18,6 @@ let
       pname = "luv";
       inherit version;
 
-      minimalOCamlVersion = "4.03";
-
       src = fetchurl {
         url = "https://github.com/aantron/luv/releases/download/${version}/luv-${version}.tar.gz";
         inherit sha256;
@@ -40,8 +37,7 @@ let
         result
       ];
       checkInputs = [ alcotest ];
-      # Alcotest depends on fmt that needs 4.08 or newer
-      doCheck = lib.versionAtLeast ocaml.version "4.08";
+      doCheck = true;
 
       meta = {
         homepage = "https://github.com/aantron/luv";