Update allowlist (#24072)

<!--Delete sections as needed -->

## Description

<!-- Tell us what you did and why -->

## Related issues or tickets

<!-- Related issues, pull requests, or Jira tickets -->

## Reviews

<!-- Notes for reviewers here -->
<!-- List applicable reviews (optionally @tag reviewers) -->

- [ ] Technical review
- [ ] Editorial review
- [ ] Product review

---------

Co-authored-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

Author: aevesdocker

content/manuals/desktop/setup/allow-list.md

@@ -33,3 +33,5 @@ This page contains the domain URLs that you need to add to a firewall allowlist
 | https://docker-pinata-support.s3.amazonaws.com                                       | Troubleshooting                              |
 | https://api.dso.docker.com                                                           | Docker Scout service                         |
 | https://api.docker.com                                                               | New API                                      |
+| https://dhi.io                                                                        | Docker Hardened Images                       |
+| https://registry.scout.docker.com                                                    | Docker Scout registry for DHI attestations   |