Update Upload-artifact to v4

Follow-up on https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/

Author: mmaylat

.github/workflows/ci.yml

@@ -40,7 +40,7 @@ jobs:
           GITHUB_TOKEN: ${{ github.token }}
 
       - name: Store Pull Request comment to be posted
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: steps.coverage_comment.outputs.COMMENT_FILE_WRITTEN == 'true'
         with:
           # If you use a different name, update COMMENT_ARTIFACT_NAME accordingly