{AKS} Fix role assignment failure caused by the breaking change of default API version bump of the auth SDK

[FumingZhang]

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This checklist is used to make sure that common guidelines for a pull request are followed.

• Fix the breaking change caused by default API version bump of the auth SDK, PR #25452.
• Update pod identity related test cases and enable these cases by default in the cli runner.
• Remove some unused role assignment related code (previously used for attach/detach acr).

Related command

az aks pod-identity

General Guidelines

• Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
• Have you run python scripts/ci/test_index.py -q locally?

For new extensions:

• My extension description/summary conforms to the Extension Summary Guidelines.

About Extension Publish

There is a pipeline to automatically build, upload and publish extension wheels.
Once your pull request is merged into main branch, a new pull request will be created to update src/index.json automatically.
You only need to update the version information in file setup.py and historical information in file HISTORY.rst in your PR but do not modify src/index.json.

[azure-client-tools-bot-prd]

Hi @FumingZhang,
If you want to release the new extension version.
Please write the description of changes into HISTORY.rst and update setup.py.

[yonzhan]

AKS

[FumingZhang]

Queued a live test pipeline to validate the change, test passed!

[azclibot]

[Release] Update index.json for extension [ aks-preview ] : https://dev.azure.com/azclitools/internal/_build/results?buildId=47908&view=results