Update to Rust 2024 edition

Formatted code.

src/testhelpers.rs

@@ -1,9 +1,9 @@
 use actix_web::{
-    body::{BoxBody, MessageBody},
     HttpResponse,
+    body::{BoxBody, MessageBody},
 };
 
-use crate::database::{models::User, UserDao};
+use crate::database::{UserDao, models::User};
 use std::cell::RefCell;
 use std::option::Option;