chore(deps): update dawidd6/action-download-artifact action to v21 (DevExpress#33697)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/_security-alerts.yml

@@ -30,7 +30,7 @@ jobs:
     needs: [ fetch ]
 
     steps:
-      - uses: dawidd6/action-download-artifact@v6
+      - uses: dawidd6/action-download-artifact@v21
         with:
           name: dependabot_alerts.json
           if_no_artifact_found: warn