chore: replace async-std with tokio (#813)

Signed-off-by: Zomatree <me@zomatree.live>

crates/delta/src/routes/account/create_account.rs

@@ -2,7 +2,7 @@
 //! POST /account/create
 use std::time::Duration;
 
-use async_std::task::sleep;
+use tokio::time::sleep;
 use revolt_config::config;
 use revolt_database::{
     util::{

crates/delta/src/routes/account/resend_verification.rs

@@ -2,7 +2,7 @@
 //! POST /account/reverify
 use std::time::Duration;
 
-use async_std::task::sleep;
+use tokio::time::sleep;
 use rocket::{serde::json::Json, State};
 use rocket_empty::EmptyResponse;
 use revolt_result::Result;

crates/delta/src/routes/account/send_password_reset.rs

@@ -2,7 +2,7 @@
 //! POST /account/reset_password
 use std::time::Duration;
 
-use async_std::task::sleep;
+use tokio::time::sleep;
 use rocket::serde::json::Json;
 use rocket::State;
 use rocket_empty::EmptyResponse;

crates/delta/src/routes/session/login.rs

@@ -3,7 +3,7 @@
 use std::ops::Add;
 use std::time::Duration;
 
-use async_std::task::sleep;
+use tokio::time::sleep;
 use iso8601_timestamp::Timestamp;
 use revolt_database::{
     util::{email::normalise_email, password::assert_safe},