chore: net8 manifest

Author: nickrandolph

build/templates/dotnet-install-windows.yml

@@ -1,7 +1,7 @@
 parameters:
   DotNetVersion: '8.0.100-rc.2.23502.2'
   UnoCheck_Version: '1.17.0-dev.3'
-  UnoCheck_Manifest: 'https://raw.githubusercontent.com/unoplatform/uno.check/2ef22f04f65ac954bf505f8ae84a366b99146d21/manifests/uno.ui-preview.manifest.json'
+  UnoCheck_Manifest: 'https://raw.githubusercontent.com/unoplatform/uno.check/519b147a80d92e35cac4b8f97855d9302c91b340/manifests/uno.ui-preview-major.manifest.json'
 
 steps: