feat: add automation for assigning aks rbac role

[amdove]

Description

Adds the AKS RBAC Cluster Admin role assignment to the resource group scope, for the ptd admin group specified in the ptd.yaml config. Follows existing role assignment patterns for Azure.

Code Flow

Category of change

• Bug fix (non-breaking change which fixes an issue)
• Version upgrade (upgrading the version of a service or product)
• New feature (non-breaking change which adds functionality)
• Build: a code change that affects the build system or external dependencies
• Performance: a code change that improves performance
• Refactor: a code change that neither fixes a bug nor adds a feature
• Documentation: documentation changes
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have reviewed my own diff and added inline comments on lines I want reviewers to focus on or that I am uncertain about