Add dotnet --info step to verify SDK installation

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

Author: Copilot

.github/copilot-setup-steps.yml

@@ -3,3 +3,4 @@ steps:
   - uses: actions/setup-dotnet@v5
     with:
       global-json-file: global.json
+  - run: dotnet --info