python313Packages.servefile: fix build

fixes https://hydra.nixos.org/build/290702043

Author: pbsds

pkgs/development/python-modules/servefile/default.nix

@@ -1,9 +1,11 @@
 {
   buildPythonPackage,
   fetchFromGitHub,
+  legacy-cgi,
   lib,
   pyopenssl,
   pytestCheckHook,
+  pythonAtLeast,
   requests,
 }:
 
@@ -19,7 +21,9 @@ buildPythonPackage rec {
     hash = "sha256-hIqXwhmvstCslsCO973oK5FF2c8gZJ0wNUI/z8W+OjU=";
   };
 
-  propagatedBuildInputs = [ pyopenssl ];
+  dependencies = [
+    pyopenssl
+  ] ++ lib.optionals (pythonAtLeast "3.13") [ legacy-cgi ];
 
   nativeCheckInputs = [
     pytestCheckHook