update AWS family policies for mid-2023 (#30)

* update AWS family policies for mid-2023

* Updated to all EC2 families as of 2023-06-23 that AWS documentation
  indicate are Nitro-based or support inherent encryption in transit.
* See https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances
  and https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/data-protection.html#encryption-transit

* updated explicit list of instance types

* Based on output of mechanical AWS CLI queries
* Note that EC2 metal instances that the documentation page claims
  are Nitro instances are no longer listed, as the query does not
  include them. Possible unintended side-effect of specific query.

* added metal instances from doc back in

* Based on discussion with Dan Miller