To fix github action warnings, upload-artifact version upgraded and d…

…ifference plots are copied only on failure, which means they would be generated and available to copy

.github/workflows/test-pr.yml

@@ -203,14 +203,14 @@ jobs:
           cp -r $GITHUB_WORKSPACE/candidate/build/Run/output_${{ matrix.configuration }}/* $GITHUB_WORKSPACE/test_report/
 
       - name: Attach diff plots to PR
-        if: ${{ always() }}
+        if: ${{ failure() }}
         run: |
           cd $GITHUB_WORKSPACE/candidate/tests/local/utils
           bash attach_all_plots.bash $(jq --raw-output .pull_request.number "$GITHUB_EVENT_PATH") ${{ matrix.configuration }}
 
       - name: Archive test results to GitHub
-        if: ${{ always() }}
-        uses: actions/upload-artifact@v3
+        if: ${{ failure() }}
+        uses: actions/upload-artifact@v4
         with:
           name: test-reports
           path: |