kanidm: require big-parallel for building (#338001)

pkgs/by-name/ka/kanidm/package.nix

@@ -122,6 +122,9 @@ rustPlatform.buildRustPackage rec {
     withSecretProvisioning = kanidm.override { enableSecretProvisioning = true; };
   };
 
+  # can take over 4 hours on 2 cores and needs 16GB+ RAM
+  requiredSystemFeatures = [ "big-parallel" ];
+
   meta = with lib; {
     changelog = "https://github.com/kanidm/kanidm/releases/tag/v${version}";
     description = "Simple, secure and fast identity management platform";