Upgrade post - Geo moves container registry to ssf

Why is this change being made?

We moved the container registry replication into the self-service framework. While this doesn't generate new capabilities it does make maintenance and support easier for the Geo team. For transparency, we want to include this change as part of the release post but it does not require the same level of impact as a release post item therefore, we want to include this note as an upgrade note.

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