Reapply "fix: change setImmediate to a 5s timeout to give plugins (or anything waiting for the return value of the API call) a chance to finish execution"

This reverts commit 8003946feb.

src/api/topics.js

@@ -85,9 +85,9 @@ topicsAPI.create = async function (caller, data) {
 	socketHelpers.notifyNew(caller.uid, 'newTopic', { posts: [result.postData], topic: result.topicData });
 
 	if (!isScheduling) {
-		setImmediate(() => {
+		setTimeout(() => {
 			activitypubApi.create.note(caller, { pid: result.postData.pid });
-		});
+		}, 5000);
 	}
 
 	return result.topicData;