automatic cargo CI changes

members/mpsc-full/src/main.rs

@@ -1,9 +1,6 @@
 //! what happens when we send a lot of items to an mpsc?
 
-use std::{
-    sync::{mpsc, Barrier},
-    thread,
-};
+use std::sync::mpsc;
 
 const NUMS: &[u8] = &[1, 3, 3, 7, 0xd, 0xe, 0xa, 0xd, 0xb, 0xe, 0xe, 0xf];