docs: fix PHPDoc types

Author: kenjis

system/Database/DataConverter/DataConverter.php

@@ -107,12 +107,12 @@ public function toDatabase(array $phpData): array
  * Add ? at the beginning of $type (i.e. ?string) to get `null`
  * instead of casting $value if ($value === null).
  *
- * @param bool|float|int|string|null $value The value to convert
- * @param string  $column The column name
- * @param string  $method Allowed to "fromDatabase" and "toDatabase"
+ * @param mixed  $value The value to convert
+ * @param string $column The column name
+ * @param string $method Allowed to "fromDatabase" and "toDatabase"
  * @phpstan-param 'fromDatabase'|'toDatabase' $method
  *
- * @return array|bool|float|int|object|string|null
+ * @return mixed
  */
  protected function castAs($value, string $column, string $method = 'fromDatabase')
  {