Bump dawidd6/action-download-artifact from 3 to 6 in /.github/workflows

Bumps [dawidd6/action-download-artifact](https://github.com/dawidd6/action-download-artifact) from 3 to 6.
- [Release notes](https://github.com/dawidd6/action-download-artifact/releases)
- [Commits](dawidd6/action-download-artifact@v3...v6)

---
updated-dependencies:
- dependency-name: dawidd6/action-download-artifact
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/upload-previews.yml

@@ -20,7 +20,7 @@ jobs:
 
       - run: pip install smokeshow
 
-      - uses: dawidd6/action-download-artifact@v3
+      - uses: dawidd6/action-download-artifact@v6
         with:
           workflow: ci.yml
           commit: ${{ github.event.workflow_run.head_sha }}