misc: Further improve imports styling

By introducing `imports_granularity="Module"` format strategy,
effectively groups imports from the same module into one line or block,
improving maintainability and readability.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

serial_buffer/src/lib.rs

@@ -3,14 +3,10 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-use std::{
-    collections::VecDeque,
-    io::Write,
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        Arc,
-    },
-};
+use std::collections::VecDeque;
+use std::io::Write;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
 
 const MAX_BUFFER_SIZE: usize = 1 << 20;