Also install .NET 8 so that Chisel.Tests don't fail on the Windows runner

Author: 0xced

.github/workflows/continuous-integration.yml

@@ -33,7 +33,9 @@ jobs:
       - name: 🧑‍🔧 Install .NET SDK
         uses: actions/setup-dotnet@v5
         with:
-          dotnet-version: 10.0.x
+          dotnet-version: |
+            10.0.x
+            8.0.x
       - name: ℹ️ Show .NET info
         run: dotnet --info
       - name: 💾 Retrieve cached NuGet packages