c-ares: ensure passthru.tests' curl is built with c-ares support

kinda pointless otherwise

pkgs/development/libraries/c-ares/default.nix

@@ -31,7 +31,8 @@ stdenv.mkDerivation rec {
   enableParallelBuilding = true;
 
   passthru.tests = {
-    inherit curl grpc;
+    inherit grpc;
+    curl = (curl.override { c-aresSupport = true; }).tests.withCheck;
   };
 
   meta = with lib; {