update to net 9

Author: taooceros

.github/workflows/dotnet.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 9.0.x
       - name: Install vpk
          Install vpk tool (dotnet tool install will not reinstall if already installed)
          We will update the cli by removing cache