Fix import path for app in target service: update import statement to correctly reference index.js

Author: austenstone

backend/src/services/target.service.ts

@@ -1,6 +1,6 @@
 import mongoose from 'mongoose';
 import adoptionService, { AdoptionType } from './adoption.service.js';
-import app from 'index.js';
+import app from '../index.js';
 import { SettingsType } from './settings.service.js';
 
 interface Target {