Use PowerShell DISM cmdlets

[Ziron]

Call DISM through built-in powershell cmdlets instead of calling the dism.exe CLI utility.

For reference:
https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/use-dism-in-windows-powershell-s14

[A1exKH]

LGTM.

[dekart811]

This should be reverted, because -StartComponentCleanup for Repair-WindowsImage doesn't exist in Windows 10 22H2 or Windows 11 23H2. So Repair-WindowsImage -Path "$mainOSDrive\scratchdir" -StartComponentCleanup -ResetBase will always fail.
So the only way to build this right now properly is by using an Windows 11 insider build, which isn't a good idea IMO.