PHP8 incompatible use of implode

[takesson]

A signature was remove from implode in PHP 8.
https://www.php.net/manual/en/function.implode.php

[13-Feb-2023 13:11:04 UTC] PHP Fatal error:  Uncaught TypeError: implode(): Argument #2 ($array) must be of type ?array, string given in /srv/cms/rweb/repos-web/open/json/listjson.php:44
Stack trace:
#0 /srv/cms/rweb/repos-web/open/json/listjson.php(44): implode()
#1 /srv/cms/rweb/repos-web/open/json/listjson.php(12): getListXml()
#2 /srv/cms/rweb/repos-web/open/json/index.php(30): getListJson()
#3 {main}
  thrown in /srv/cms/rweb/repos-web/open/json/listjson.php on line 44