Upgrade to 3.9.8

kirby/vendor/symfony/yaml/Inline.php

@@ -60,6 +60,10 @@ class Inline
      */
     public static function parse(string $value = null, int $flags = 0, array &$references = [])
     {
+        if (null === $value) {
+            return '';
+        }
+
         self::initialize($flags);
 
         $value = trim($value);