Dependabot: add note about IP allowlist (github#19958)

* Dependabot: add note about IP allowlist

We sometimes get questions from customers using private registries about adding dependabot to their ip-allowlist. We expose the IP addresses that dependabot makes updates from in our API, this explains that

* Apply suggestions from code review

* Apply suggestions from code review

* Update content/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/managing-encrypted-secrets-for-dependabot.md

Co-authored-by: mc <42146119+mchammer01@users.noreply.github.com>

Author: jurre

content/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/managing-encrypted-secrets-for-dependabot.md

@@ -79,3 +79,7 @@ When creating a secret in an organization, you can use a policy to limit which r
    The name of the secret is listed on the Dependabot secrets page. You can click **Update** to change the secret value or its access policy. You can click **Remove** to delete the secret.
 
    ![Update or remove an organization secret](/assets/images/help/dependabot/update-remove-repo-secret.png)
+   
+## Adding {% data variables.product.prodname_dependabot %} to your registries IP allow list
+
+If your private registry is configured with an IP allow list, you can find the IP addresses {% data variables.product.prodname_dependabot %} uses to access the registry in the meta API endpoint, under the `dependabot` key. For more information, see "[Meta](/rest/reference/meta)."