Adds missing ref to the 8.16.1 release notes (backport #6225)

[mergify]

Updates the release notes landing page for 8.17 and 8.x so they're no longer missing the reference to the 8.16.1 release notes.

Previews: 8.x RN landing page

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This is an automatic backport of pull request #6225 done by Mergify.

[github-actions]

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