CCM-8861: Fix eventbridge event

Author: chris-elliott-nhsd

lambdas/sftp-letters/src/api/sftp-poll.ts

@@ -1,12 +1,10 @@
 import type { Container } from '../container-poll';
 
 type EventBridgeEvent = {
-  event: {
     supplier: string;
-  };
 };
 
 export const createHandler =
   ({ app }: Container) =>
-  ({ event: { supplier } }: EventBridgeEvent) =>
+  ({ supplier }: EventBridgeEvent) =>
     app.poll(supplier);