The GET /v3/OS-FEDERATION/projects and GET /v3/OS-FEDERATION/domains
APIs were introduced to handle tokens from federated users, but now
that GET /v3/auth/projects and GET /v3/auth/domains know how to handle
federated tokens, they're just duplicate APIs.
In the past we deprecated these federated auth APIs, but they still
used separate code paths from GET /v3/auth/projects and GET
/v3/auth/domains. The two code paths are true duplication in that they
don't expect to differ over time and should provide the same user
Instead of running the risk that comes with two code paths that do the
same thing, we should consolidate them.
Co-Authored-By: Kristi Nikolla <email@example.com>