[testlib] Add ssh_audit test to hpctestlist

[victorusu]

The test downloads the ssh-audit tool from GitHub and checks if there is any configuration that is considered as a failure.

The test is compatible with all the job schedulers. Because it only checks the localhost, where the test script runs. So, it becomes the responsibility of ReFrame to spawn the test script in the desired systems.

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (38cc61a) 87.35% compared to head (0caf47a) 87.36%.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #2956   +/-   ##
========================================
  Coverage    87.35%   87.36%           
========================================
  Files           60       60           
  Lines        11683    11687    +4     
========================================
+ Hits         10206    10210    +4     
  Misses        1477     1477           

see 2 files with indirect coverage changes

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[vkarak]

Also, have you checked the docs? Do these tests' docs appear correctly in the lib docs?