```release-note:enhancement
resource/aws_elasticache_cluster: Add `ip_discovery` and `network_type` arguments in support of [IPv6 clusters](https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/network-type.html)
```

```release-note:enhancement
data-source/aws_elasticache_cluster: Add `ip_discovery` and `network_type` attributes
```