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

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

crates/core/database/src/tasks/ack.rs

@@ -305,6 +305,6 @@ pub async fn worker(db: Database, amqp: AMQP) {
         }
 
         // Sleep for an arbitrary amount of time.
-        async_std::task::sleep(Duration::from_secs(1)).await;
+        tokio::time::sleep(Duration::from_secs(1)).await;
     }
 }

crates/core/database/src/tasks/last_message_id.rs

@@ -82,6 +82,6 @@ pub async fn worker(db: Database) {
         }
 
         // Sleep for an arbitrary amount of time.
-        async_std::task::sleep(Duration::from_secs(1)).await;
+        tokio::time::sleep(Duration::from_secs(1)).await;
     }
 }

crates/core/database/src/tasks/mod.rs

@@ -2,7 +2,7 @@
 
 use crate::{Database, AMQP};
 
-use async_std::task;
+use tokio::task;
 use std::time::Instant;
 
 const WORKER_COUNT: usize = 5;

crates/core/database/src/tasks/process_embeds.rs

@@ -7,11 +7,11 @@ use revolt_config::config;
 use revolt_result::Result;
 
 use async_lock::Semaphore;
-use async_std::task::spawn;
 use deadqueue::limited::Queue;
 use once_cell::sync::Lazy;
 use revolt_models::v0::Embed;
 use std::{collections::HashSet, sync::Arc};
+use tokio::task::spawn;
 
 use isahc::prelude::*;
 
@@ -159,6 +159,7 @@ pub async fn generate(
         .await
         .into_iter()
         .flatten()
+        .flatten()
         .collect::<Vec<Embed>>();
 
     // Prevent database update when no embeds are found.