And now force 8 onto the runner for tests

Author: blowdart

.github/workflows/ci-build.yml

@@ -39,6 +39,10 @@ jobs:
 
     - name: 'Setup .NET SDK'
       uses: actions/setup-dotnet@67a3573c9a986a3f9c594539f4ab511d57bb3ce9 # v4.3.1
+      with:
+        dotnet-version: | 
+          8.0.x
+          9.0.x
 
     - name: 'Restore external dependencies'
       run: dotnet restore