Fix codex-auth test import ordering

Apply the rustfmt import ordering expected by CI for the moved token data tests.

Co-authored-by: Codex <noreply@openai.com>

codex-rs/codex-auth/src/token_data_tests.rs

@@ -1,5 +1,5 @@
-use base64::Engine;
 use super::token_data::*;
+use base64::Engine;
 use pretty_assertions::assert_eq;
 use serde::Serialize;