Not Removing Previous Roles and Users within iamAuthenticatorConfig

[wcrum]

/kind bug

What steps did you take and what happened:
Updating iamAuthenticatorConfig with multiple roles or users, then removing roles does not remove old roles and users, only appends new arns.

1. Define CAPA iamAuthenticatorConfig.

iamAuthenticatorConfig:
  mapUsers:
  - groups:
    - system:masters
    userarn: arn:aws:iam::111122223333:user/my-user
    username: my-user
  - groups:
    - system:masters
    userarn: arn:aws:iam::111122223333:user/my-second-user
    username: my-second-user

2. Define iamAuthenticatorConfig removing a user.

iamAuthenticatorConfig:
  mapUsers:
  - groups:
    - system:masters
    userarn: arn:aws:iam::111122223333:user/my-second-user
    username: my-second-user

3. Result within kube-system/aws-auth.

   mapUsers: |                                                                                                                                                                            
     - groups:                                                                                                                                                                           
       - system:masters                                                                                                                                                                   
       userarn: arn:aws:iam::111122223333:user/my-user                                                                                                                                     
       username: my-user
     - groups:                                                                                                                                                                           
       - system:masters                                                                                                                                                                   
       userarn: arn:aws:iam::111122223333:user/my-second-user                                                                                                                                 
       username: my-second-user

What did you expect to happen:
The expected behavior is to have kube-system/aws-auth to only have the defined users / roles.

   mapUsers: |                                                                                                                                                                            
     - groups:                                                                                                                                                                           
       - system:masters                                                                                                                                                                   
       userarn: arn:aws:iam::111122223333:user/my-second-user                                                                                                                                 
       username: my-second-user

Anything else you would like to add:
Would like to clarify if this is expected or unexpected behavior. Not removing users / roles could be a security risk.

Environment:

• Cluster-api-provider-aws version: v2.3.1
• Kubernetes version: (use kubectl version): v1.28.4
• OS (e.g. from /etc/os-release): macOS 14.1.1 (23B81)

[k8s-triage-robot]

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/lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle rotten
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle rotten

[nrb]

/remove-lifecycle rotten
/triage accepted