chore(ci): bump dawidd6/action-download-artifact from 5 to 6

Bumps [dawidd6/action-download-artifact](https://github.com/dawidd6/action-download-artifact) from 5 to 6.
- [Release notes](https://github.com/dawidd6/action-download-artifact/releases)
- [Commits](dawidd6/action-download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: dawidd6/action-download-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/optimizer.yml

@@ -73,7 +73,7 @@ jobs:
         # for artifacts restrictions see https://github.com/actions/download-artifact/issues/3
         # for cache restrictions see https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#restrictions-for-accessing-a-cache
         # and  https://github.com/actions/cache/issues/692
-        uses: dawidd6/action-download-artifact@v5
+        uses: dawidd6/action-download-artifact@v6
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           workflow_conclusion: ""