`CodexAuth::new()` was the first method listed in `CodexAuth`, but it is only meant to be used by tests. Rename it to `create_dummy_chatgpt_auth_for_testing()` and move it to the end of the implementation. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/openai/codex/pull/1962). * #1971 * #1970 * #1966 * #1965 * __->__ #1962