message: spectest: skip on unsupported_feature error
diff: @@ -378,8 +378,16 @@ private:
  args.push_back(arg_value);
  }
  + try
  + {
  return fizzy::execute(*instance, *func_idx, std::move(args));
  }
  + catch (fizzy::unsupported_feature const& ex)
  + {
  + skip(std::string{"Unsupported feature: "} + ex.what());
  + return std::nullopt;
  + }
  + }
  bool check_result(uint64_t actual_value, const json& expected)
  {
  