fix(dal): remove unused composite index from notification template schema

Author: merrcury

libs/dal/src/repositories/notification-template/notification-template.schema.ts

@@ -271,11 +271,6 @@ notificationTemplateSchema.index({
   name: 1,
 });
 
-notificationTemplateSchema.index({
-  _environmentId: 1,
-  'triggers.identifier': 1,
-});
-
 notificationTemplateSchema.plugin(mongooseDelete, { deletedAt: true, deletedBy: true, overrideMethods: 'all' });
 
 export const NotificationTemplate =