Update tox setup for AWS Lambda integration

[antonpirker]

Because we changed our AWS Lambda test suite to not create real Lambda functions but rather run a Lambda environment locally, we do not need all the code necessary for handling the authentication to AWS in the test suite.

This PR removes all the AWS auth related code and als moves the AWS Lambda testsuite again into the "Cloud" group of test suites, because it is a "normal" test suite again.

The PR that includes the change to have a local Lambda environment is here: #3988

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.49%. Comparing base (38fa8c0) to head (bad4994).
Report is 1 commits behind head on antonpirker/better-aws-tests.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@                       Coverage Diff                        @@
##           antonpirker/better-aws-tests    #4076      +/-   ##
================================================================
+ Coverage                         79.46%   79.49%   +0.03%     
================================================================
  Files                               140      140              
  Lines                             15521    15521              
  Branches                           2631     2631              
================================================================
+ Hits                              12334    12339       +5     
+ Misses                             2353     2351       -2     
+ Partials                            834      831       -3     

see 2 files with indirect coverage changes

[sentrivana]

#feelsgood

There is couple more aws-* scripts in scripts/, do we still need any of those?

[antonpirker]

Those scripts are still needed if someone is doing manual testing (creating a Lambda function by hand and wanting to add the Layer to it and stuff like this)

I cleaned the scripts/ directory up a bit (and removed some other Lambda function that is not necessary anymore.