feat(iam): add new check iam_policy_cloudshell_admin_not_attached

[MarioRgzLpz]

Context

Add a new check to ensure IAM identities (users, roles, or groups) don't have the AWS managed policy AWSCloudShellFullAccess attached. The control fails if this policy is present.

AWSCloudShellFullAccess provides full access to AWS CloudShell, including file upload/download capabilities and sudo permissions, which can pose security risks. Adhere to the principle of least privilege and avoid attaching this broad policy.

Description

Added new check iam_cloudshell_admin_policy_not_attached with respective unit tests. Added new attribute entities_attached_to_cloudshell_policy with method _list_entities_for_policy and a test for the method.

Checklist

• Are there new checks included in this PR? Yes
  • If so, do we need to update permissions for the provider? No.
• Review if the code is being covered by tests.
• Review if code is being documented following this specification https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings
• Review if backport is needed.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Attention: Patch coverage is 90.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 89.57%. Comparing base (45c32ab) to head (d288376).
Report is 38 commits behind head on master.

Files with missing lines	Patch %	Lines
prowler/providers/aws/services/iam/iam_service.py	80.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5437      +/-   ##
==========================================
+ Coverage   89.21%   89.57%   +0.36%     
==========================================
  Files        1044     1067      +23     
  Lines       32225    33080     +855     
==========================================
+ Hits        28750    29633     +883     
+ Misses       3475     3447      -28     

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