clippy: changes from nightly clippy

all of this is embeding teh var into teh format macro

src/bin/update_users.rs

@@ -40,7 +40,7 @@ async fn main() {
   }
 
   if let Err(why) = client.start().await {
-    println!("Client error: {:?}", why);
+    println!("Client error: {why:?}");
   }
 }