Bump actions/download-artifact from 3 to 4 (#356)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v3...v4)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/testing-and-deployment.yml

@@ -160,7 +160,7 @@ jobs:
   #       run: ls -R
 
   #     - name: Downloading artifacts
-  #       uses: actions/download-artifact@v3
+  #       uses: actions/download-artifact@v4
 
   #     - name: Display structure of downloaded artifact files
   #       run: ls -R
@@ -232,7 +232,7 @@ jobs:
           python-version: '3.11'
 
       # this downloads all artifacts
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
 
       - name: Display structure of downloaded files
         run: ls -R