Datadog SLOs do not support `time_slice` type

There should be am entry for [time slice slos](https://docs.datadoghq.com/service_management/service_level_objectives/time_slice/)

```typescript
export declare enum CfnSloPropsType {
/** monitor */
MONITOR = "monitor",
/** metric */
METRIC = "metric"
}
```

like there is for [terraform](https://registry.terraform.io/providers/DataDog/datadog/latest/docs/resources/service_level_objective#type) already