Noticed when adding some new standard plugins in MDL-78427 & MDL-80544

https://github.com/moodle/moodle/blob/3fc907e3d8646d53b744cbeb2820f5a060cc86ee/lib/classes/plugin_manager.php#L1723-L1733

Note that 'qformat' key is defined twice

See https://3v4l.org/4rRqm for example of what PHP does with this (& also MDL-79717 which describes the same problem in unit test data providers)

Unclear what practical impact this has, but it's clearly wrong currently so we should fix that