add aws credentials to circleci system tests

[wconti27]

Description

add necessary auth for new aws system tests and add IDM scenarios of interest

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.49%. Comparing base (501f386) to head (1b68009).

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #2857   +/-   ##
=========================================
  Coverage     78.49%   78.49%           
  Complexity     2517     2517           
=========================================
  Files           173      173           
  Lines         18683    18683           
  Branches        975      975           
=========================================
  Hits          14665    14665           
  Misses         3481     3481           
  Partials        537      537           

Flag	Coverage Δ
appsec-extension	69.12% <ø> (ø)
tracer-extension	78.18% <ø> (ø)
tracer-php	82.27% <ø> (ø)

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[bwoebi]

I sort-of don't really like having more secrets than needed in CI. What do we need aws credentials for, in system tests?
Can't these tests run locally, somehow? I'd strongly prefer having tests without external dependencies.

[wconti27]

I sort-of don't really like having more secrets than needed in CI. What do we need aws credentials for, in system tests? Can't these tests run locally, somehow? I'd strongly prefer having tests without external dependencies.

@bwoebi We need AWS tests for correctly testing propagation between Lambda and messaging systems (SQS, SNS, Kinesis). The previous 3rd party software that we were using (Localstack) was not cutting it. It was not a 1 to 1 matchup of feature support compared to actual AWS, and was providing both false negatives and false positives for our tests. This change has already been made in the other tracers.

[bwoebi]

Okay, let's merge it.
But definitely first merge conti/fix-php-errors on the system-tests repo.