Upgrade to AWS SDK 3

[jaytmiller]

First off, thanks for awsudo, it's great stuff and we use it all the time and it makes our lives easier!

I don't consider this issue to be a bug in awsudo but it does seem like an area of growth AWS is pushing forcefully: upgrade AWS SDK apps to v3 or suffer this message whenever you run your app:

(node:89340) NOTE: We are formalizing our plans to enter AWS SDK for JavaScript (v2) into maintenance mode in 2023.

Please migrate your code to use AWS SDK for JavaScript (v3).
For more information, check the migration guide at https://a.co/7PzMCcy
(Use `node --trace-warnings ...` to show where the warning was created)

Since this output appears every time awsudo runs, it is distracting and breaks some automated use cases which depend on the output from the command awsudo is used to run.

Given that https://a.co/7PzMCcy shows a migration tool, hopefully updating is not too hard or blocked by other concerns. Unfortunately I don't have the Javascript skills to offer a PR personally.

Lastly for other users who'd rather not see this AWS message, there is this fairly simple fix to suppress it:

export AWS_SDK_JS_SUPPRESS_MAINTENANCE_MODE_MESSAGE=1