Fix: findVisualStudio with pwsh constrained lang. mode

'Add-Type' cannot be used in powershell with constrained language mode. Language mode does not exist in PowerShell 2.0 engine. To force powershell to use 2.0 engine allows the usage of msvc 2017 or newer in environment with constrained language mode.
See : 
https://devblogs.microsoft.com/powershell/powershell-constrained-language-mode/
https://docs.microsoft.com/en-us/powershell/scripting/windows-powershell/starting-the-windows-powershell-2.0-engine?view=powershell-7.1

Author: lucascloarec

lib/find-visualstudio.js

@@ -129,6 +129,8 @@ VisualStudioFinder.prototype = {
       'WindowsPowerShell', 'v1.0', 'powershell.exe')
     var csFile = path.join(__dirname, 'Find-VisualStudio.cs')
     var psArgs = [
+      '-Version',
+      '2',
       '-ExecutionPolicy',
       'Unrestricted',
       '-NoProfile',