Update dotnetcore.yml

Needed for .NET CDN change

see dotnet/core#9671

and: AzureAD/microsoft-identity-web#3175

Signed-off-by: Keegan <[email protected]>

Author: keegan-caruso

.github/workflows/dotnetcore.yml

@@ -11,7 +11,7 @@ jobs:
     - name: Checkout repository
       uses: actions/[email protected]     
     - name: Setup .NET 8.0.x
-      uses: actions/setup-dotnet@v1.7.2
+      uses: actions/setup-dotnet@v4
       with:
         dotnet-version: 8.0.x