Update CI workflow to use actions/upload-artifact@v4

Author: tryb3l

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
 
       - name: Publish test results
         if: always()
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: test-results
           path: "**/TestResults/*.trx"