update opis/json-schema to 2.3.0, fixes #4173

RELEASE-NOTES.md

composer.json

composer.lock

lib/models/Courseware/BlockTypes/Audio.php

lib/models/Courseware/BlockTypes/BeforeAfter.php

lib/models/Courseware/BlockTypes/BiographyAchievements.php

lib/models/Courseware/BlockTypes/BiographyCareer.php

lib/models/Courseware/BlockTypes/BiographyGoals.php

...ls/Courseware/BlockTypes/BiographyPersonalInformation.php

lib/models/Courseware/BlockTypes/BlockType.php

lib/models/Courseware/BlockTypes/Canvas.php

lib/models/Courseware/BlockTypes/Chart.php

lib/models/Courseware/BlockTypes/Code.php

lib/models/Courseware/BlockTypes/Confirm.php

lib/models/Courseware/BlockTypes/Date.php

lib/models/Courseware/BlockTypes/DialogCards.php

lib/models/Courseware/BlockTypes/Document.php

lib/models/Courseware/BlockTypes/Download.php

lib/models/Courseware/BlockTypes/Embed.php

lib/models/Courseware/BlockTypes/Error.php