Bump version for download and upload artifact (#751)

Author: kylebarron

.github/workflows/release.yml

@@ -44,18 +44,19 @@ jobs:
           # If no files with path lonboard/static, fail
           unzip -l dist/*.whl | grep "lonboard/static" || exit 1
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           path: ./dist/
 
   upload_pypi:
     needs: [build]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: artifact
           path: dist
+          merge-multiple: true
 
       - uses: pypa/gh-action-pypi-publish@release/v1
         with: