Azure Virtual Desktop basicscale.ps1 does not work with user assigned or managed identities

[al-lac]

Azure Run as accounts will be retired on September 30 2023. The script basicScale.ps1 will not work anymore from this point on.

Support for user assigned and managed identities is needed until then.

I got it working with managed identities by the "region azure auth, ctx" with the following:

	#region azure auth, ctx

	if (!$SkipAuth) {
		# Azure auth
		$AzContext = $null
		try {
			$AzAuth = Connect-AzAccount -Identity
			if (!$AzAuth -or !$AzAuth.Context) {
				throw $AzAuth
			}
			$AzContext = $AzAuth.Context
		}
		catch {
			throw [System.Exception]::new('Failed to authenticate Azure with managed identity', $PSItem.Exception)
		}
		Write-Log "Successfully authenticated with Azure using managed identity: $($AzContext | Format-List -Force | Out-String)"
	}

	#endregion`