Consider using secretbox instead of aescbc for etcd encryption

[Preisschild]

Feature Request

Description

Talos currently uses the aescbc provider for etcd encryption.

The official documentation does not recommend using this anymore due to it being vulnerable to padding oracle attacks and thus rates it as "Weak". A newer option would be secretbox, which is currently rated "Strong" in the Kubernetes documentation

More Information

• https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/#providers