Unable to list feeds - alerts with "Error - 200: OK" with php 8.2 #36

Discovered on a fresh install of Emoncms using emonScripts updated to support php8.2 on Debian 12 "bookworm". Navigating to the Sync page displays a JavaScript alert "Error - 200: OK" and does not list feeds when the connection details for another emoncms are provided.

Investigating the response for the /sync/feed-list request shows a php warning:

<br />
<b>Deprecated</b>:  Creation of dynamic property Sync::$feed is deprecated in <b>/opt/emoncms/modules/sync/sync-module/sync_model.php</b> on line <b>29</b><br />
{"enphase_panel\/Back_East_LRW":...}