Escape inline pwsh variable

Author: Arlodotexe

.github/workflows/build.yml

@@ -160,7 +160,7 @@ jobs:
 
       - name: Validate package names
         if: ${{ env.VERSION_PROPERTY != '' }}
-        run: powershell -version 5.1 -command "Get-ChildItem -Path '**/*.nupkg' | ForEach-Object { if ($_.Name -notmatch '${{ env.VERSION_PROPERTY }}') { throw 'Nupkg name is missing trailing VERSION_PROPERTY' + $_.Name } }" -ErrorAction Stop
+        run: powershell -version 5.1 -command "Get-ChildItem -Path '**/*.nupkg' | ForEach-Object { if (`$_.Name -notmatch '${{ env.VERSION_PROPERTY }}') { throw 'Nupkg name is missing trailing VERSION_PROPERTY' + `$_.Name } }" -ErrorAction Stop
 
       # Push Pull Request Packages to our DevOps Artifacts Feed (see nuget.config)
       - name: Push PR packages (if not fork)