Bump actions/download-artifact from 3 to 4 in /.github/workflows (#169)

* Bump actions/download-artifact from 3 to 4.1.7 in /.github/workflows

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 3 to 4.1.7.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v3...v4.1.7)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update version

* Update upload action

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Isabel Paredes <isabel.paredes@quantstack.net>

.github/workflows/build.yml

@@ -39,7 +39,7 @@ jobs:
         pip uninstall -y jupyros jupyterlab
 
     - name: Upload extension packages
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: extension-artifacts
         path: dist/jupyros*
@@ -57,7 +57,7 @@ jobs:
       with:
         python-version: '3.10'
         architecture: 'x64'
-    - uses: actions/download-artifact@v3
+    - uses: actions/download-artifact@v4
       with:
         name: extension-artifacts
     - name: Install and Test