fix(RSS Feed Trigger Node): Use newest date instead of first item for…

… new items (#9182)

Co-authored-by: Jonathan Bennetts <jonathan.bennetts@gmail.com>

packages/nodes-base/nodes/RssFeedRead/RssFeedReadTrigger.node.ts

@@ -76,7 +76,10 @@ export class RssFeedReadTrigger implements INodeType {
 					returnData.push(item);
 				}
 			});
-			pollData.lastItemDate = feed.items[0].isoDate;
+			const maxIsoDate = feed.items.reduce((a, b) =>
+				new Date(a.isoDate as string) > new Date(b.isoDate as string) ? a : b,
+			).isoDate;
+			pollData.lastItemDate = maxIsoDate;
 		}
 
 		if (Array.isArray(returnData) && returnData.length !== 0) {