Update 3.16.1 release notes about secret scanning issue (#55143)

Co-authored-by: june1963 <[email protected]>
Co-authored-by: Vanessa <[email protected]>

Author: 3 people

data/release-notes/enterprise-server/3-16/1.yml

@@ -28,6 +28,8 @@ sections:
     - |
       Update the bundled `actions/setup-dotnet` with the latest versions from https://github.com/actions/setup-dotnet.
   known_issues:
+    - |
+      Upgrades to 3.16.1 may fail due to an error while migrating a secret scanning database. The `ghe-migrations` command output will include a `DelegatedBypassConfigurationNotNil` error. To recover, you can restore from a backup, fail over to a replica, or reach out to GitHub Support if you encounter this issue. [Updated: 2025-04-03]
     - |
       Custom firewall rules are removed during the upgrade process.
     - |