Remove six and msrest dependencies

[kshitij-microsoft]

Description

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[Copilot]

Pull Request Overview

This PR aims to simplify dependency management by removing the msrest and six dependencies from the Azure ML SDK setup configuration.

• Removed msrest dependency from the install_requires list.
• Removed six dependency and its associated TODO comment.

Comments suppressed due to low confidence (2)

sdk/ml/azure-ai-ml/setup.py:71

• Please ensure that any code using msrest has been updated to use an alternative, as the dependency has been removed.

"msrest>=0.6.18,<1.0.0",

sdk/ml/azure-ai-ml/setup.py:89

• Verify that all usages of six have been removed or replaced since its dependency and the associated TODO comment have been removed.

"six>=1.11.0",