fix(ci): remove empty checkout 'with' and install net8 + net10 runtimes

Author: RoboNET

.github/workflows/ci.yml

@@ -18,12 +18,13 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-        with:
 
       - name: Setup .NET
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: '10.0.x'
+          dotnet-version: |
+            8.0.x
+            10.0.x
 
       - name: Restore
         run: dotnet restore FlexRender.slnx