The JAuthentication class requires manual import and the file that holds this class contains two classes (JAuthentication and JAuthenticationResponse). Move the file so it can be autoloaded and split the response class to a new file to follow the one class per file convention.
Testing Instructions
User authentication still works correctly, on update the old file is deleted.
I have tested this item✅ successfully on 3233daa
I have Joomla Authentication Plugin enabled and user authentication works correctly after applying patch too.
This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/11023.