Temporarily disable config clean-up

The current query doesn't work in MySQL 8.

backend/src/data/cleanup/configs.ts

@@ -9,6 +9,9 @@ const CLEAN_PER_LOOP = 50;
 export async function cleanupConfigs() {
   const configRepository = getRepository(Config);
 
+  // FIXME: The query below doesn't work on MySQL 8.0. Pending an update.
+  return;
+
   let cleaned = 0;
   let rows;