update to Az PowerShell

[petrce]

Hi @pascalnaber ,
Since AzureRM is now obsolete, we migrated our build agents and our scripts to Az Powershell.
Do you plan to migrate this task to Az Powershell? You cant have AzureRM and Az Powershell on the same machine :-/
Thanks

Source:
https://docs.microsoft.com/en-us/powershell/azure/azurerm/overview?view=azurermps-6.13.0