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/ci.yml

@@ -79,7 +79,7 @@ jobs:
       run: vendor/bin/phpunit --configuration phpunit.xml --bootstrap build/autoload.php
 
     - name: Download base coverage
-      uses: dawidd6/action-download-artifact@v3
+      uses: dawidd6/action-download-artifact@v6
       if: github.event_name == 'pull_request' && matrix.phar == false
       continue-on-error: true
       with: