Update dependencies to use aws sdk v2

[mabels]

in preparation to the aws ses receive observer.

What is an aws ses receive oberserver? i will receive the emails via s3 and sqs and forward them locally. This should enable to run a public smtp server behind aws ses. So to run a public smtp it does not have to expose outbound or an inbound public smtp port. The part of the outbound email is done by the current implementation.