Try switch to use Powershell with windows 2022.

Author: Layoric

.github/workflows/static.yml

@@ -41,7 +41,7 @@ jobs:
           dotnet-version: '6.x'
       - name: Download docfx
         run: |
-          client = new-object System.Net.WebClient
+          $client = new-object System.Net.WebClient
           $client.DownloadFile("https://github.com/dotnet/docfx/releases/download/v2.59.4/docfx.zip")
       - name: Setup docfx
         run: |