Add auth.docker.com in Desktop firewall allow list (#22874)

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## Description

The flow for Desktop auth has changed and follows some redirects to
auth.docker.com

## Related issues or tickets

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## Reviews

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

Signed-off-by: Guillaume Tardif <guillaume.tardif@gmail.com>

Author: gtardif

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

@@ -24,6 +24,7 @@ This page contains the domain URLs that you need to add to a firewall allowlist
 | https://auth.docker.io                                                               | Authentication                               |
 | https://cdn.auth0.com                                                                | Authentication                               |
 | https://login.docker.com                                                             | Authentication                               |
+| https://auth.docker.com                                                              | Authentication                               |
 | https://desktop.docker.com                                                           | Update                                       |
 | https://hub.docker.com                                                               | Docker Hub                                   |
 | https://registry-1.docker.io                                                         | Docker Pull/Push                             |