Update rust dependencies for next release

[jpculp]

Issue number:

#2412

Description of changes:

Ran cargo update for sources and tools, while adjusting the deny and clarify TOMLs as necessary.

Also normalized the deny TOMLs for consistency.

Testing done:
Built aws-k8s-1.21 (x86_64) and aws-ecs-1 (aarch64). Verified there were no issues in systemctl, the api client, and using apiclient exec to interact with the host containers.

Also verified TUF repos with cargo make repo, cargo make validate-repo, and cargo make check-repo-expirations.

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[jpculp]

I'm going to wait and bump AWS SDK for Rust once #2414 is merged and we bump tough and coldsnap, but I'd like to get these updates in now.

[jpculp]

Removed structopt-derive skip-tree since it's already taken care of by the structopt skip-tree.

[stmcginnis]

Seems fine and jobs are happy. Would be good to get this in quickly so we can watch for any unintended side effects and have time to address them if so.