Remove JSON +json subtype handling

Author: sirreal

src/wp-includes/html-api/class-wp-html-tag-processor.php

@@ -4091,14 +4091,16 @@ public function is_json_script_tag(): bool {
 		 * > A JSON MIME type is any MIME type whose subtype ends in "+json" or whose essence
 		 * > is "application/json" or "text/json".
 		 *
+		 * The JSON subtype ending in "+json" is not currently handled due to lack
+		 * of a MIME type parser.
+		 *
 		 * @see https://mimesniff.spec.whatwg.org/#json-mime-type
 		 */
 		if (
 			'application/json' === $type_string
 			|| 'importmap' === $type_string
 			|| 'speculationrules' === $type_string
 			|| 'text/json' === $type_string
-			|| str_ends_with( $type_string, '+json' )
 		) {
 			return true;
 		}