ctype_digit(): Argument of type int will be interpreted as string in the future

[janboddez]

class-block-editor.php:111

[janboddez]

It would seem that WP_REST_Request::get_param() already converts "integer strings" to ints.

[janboddez]

Or rather, this is JSON, not a regular form input. That explains. It was an int all along.

So we can simply use is_int() and return early if it isn't, which should never happen.