If a request isn't set (edge case) the value of content type doesn't exist.
NOTICE: PHP message: PHP Notice: Trying to access array offset on value of type null in /usr/local/wordpress/vendor/ironbound/wp-rest-api-schema-validator/src/Middleware.php on line 830
If a request isn't set (edge case) the value of content type doesn't exist.
https://github.com/iron-bound-designs/wp-rest-api-schema-validator/blob/c5452e3ae972a13a1581a219c96c4cf1c81d5e60/src/Middleware.php#L830