What's Changed
* Fix `_replace_field_names_case_insensitively` precondition inconsistency by AlexVndnblcke in https://github.com/pydantic/pydantic-settings/pull/130
* Check union args to don't consider Optional fields as complex Union by hramezani in https://github.com/pydantic/pydantic-settings/pull/138
New Contributors
* AlexVndnblcke made their first contribution in https://github.com/pydantic/pydantic-settings/pull/130
**Full Changelog**: https://github.com/pydantic/pydantic-settings/compare/v2.0.2...v2.0.3