Description of problem:

Redmine #36827 updated tokens returned during authentication to match OAuth2 specs required by docker. This involved changing the `expires_at` field to an `expires_in` field. We kept the former field to maintain compatibility with existing smart proxies during 4.11 upgrades. It should be removed in 4.13 or later.

How reproducible:

Always

Is this issue a regression from an earlier version:

No

Steps to Reproduce:

1. Authenticate with podman CLI and view the returned token.

Actual behavior:
expires_at is an included field.

Expected behavior:
expires_at should not be included.

Business Impact / Additional info: