Add new US PubSec Services SET stable counterpart

Why is this change being made?

Welcome @bwilkerson13!

Adding Brittany to the groups definition should increase visibility of the stable counterpart relationship. We try to keep this page up-to-date.

I'm adding this entry based to this comment: https://gitlab.com/gitlab-org/gitlab/-/issues/386087#note_1214991873.

Author Checklist

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