Remove line that doesn't work on pwsh

Expand-Template.ps1

@@ -148,7 +148,6 @@ try {
     Replace-Placeholders -Path "azure-pipelines.yml" -Replacements $YmlReplacements
 
     # Self destruct
-    $Invocation = (Get-Variable MyInvocation -Scope 1).Value
     git rm Expand-Template.*
     git rm :/azure-pipelines/expand-template.yml