remove more redundant imports

Author: matheus-consoli

src/concurrent_stream/for_each.rs

@@ -163,7 +163,6 @@ mod test {
     use super::*;
     use crate::prelude::*;
     use futures_lite::stream;
-    use std::sync::Arc;
 
     #[test]
     fn concurrency_one() {

src/concurrent_stream/try_for_each.rs

@@ -196,7 +196,7 @@ mod test {
     use super::*;
     use crate::prelude::*;
     use futures_lite::stream;
-    use std::{io, sync::Arc};
+    use std::io;
 
     #[test]
     fn concurrency_one() {