Disable eks-pod-identity-agent check in case of EKS auto mode

[TarmoKople]

Description

Fixes the error:

eksctl create podidentityassociation  .....            
Error: the "eks-pod-identity-agent" addon must be installed to create pod identity associations; please enable it using `eksctl ....

eksctl does not check whether EKS is using auto-mode or not. In EKS auto-mode, there is no need to check whether the eks-pod-identity-agent is installed or not, because eks-pod-identity-agent is part of the EKS auto-mode.
I added a check to the IsPodIdentityAgentInstalled function that verifies if the EKS cluster is using auto-mode and, if necessary, skips the check for the eks-pod-identity-agent.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the userdocs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes
• (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[github-actions]

Hello TarmoKople 👋 Thank you for opening a Pull Request in eksctl project. The team will review the Pull Request and aim to respond within 1-10 business days. Meanwhile, please read about the Contribution and Code of Conduct guidelines here. You can find out more information about eksctl on our website

[cheeseandcereal]

Thanks for the change! This solution seems reasonable to me, but this change is breaking unit tests. Can you fix the unit tests?

[TarmoKople]

Thanks for the change! This solution seems reasonable to me, but this change is breaking unit tests. Can you fix the unit tests?

Yes, I'm going to fix the unit tests.

[naclonts]

Another PR was merged in with a similar fix: #8358

Thank you @TarmoKople for the PR as well! If you see any other issues feel free to open a new PR or GitHub Issue.