Update Validate-NDESConfiguration.ps1

[Jack-Ed]

Get-WmiObject is depracated (https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/get-wmiobject?view=powershell-5.1)

This caused an issue when running with PowerShell 7 as a I received: The term 'Get-WmiObject' is not recognized as a name of a cmdlet, function, script file, or executable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.

Replaced: (Get-WmiObject Win32_ComputerSystem).domain

With: (Get-ADDomain).DNSRoot