Turbopack: use unstable sort for better performance (#78764)

### What?

Small performance improvement by using unstable sort

Author: sokra

turbopack/crates/turbo-persistence/src/collector.rs

@@ -93,7 +93,7 @@ impl<K: StoreKey, const SIZE_SHIFT: usize> Collector<K, SIZE_SHIFT> {
     /// Sorts the entries and returns them along with the total key and value sizes. This doesn't
     /// clear the entries.
     pub fn sorted(&mut self) -> (&[CollectorEntry<K>], usize, usize) {
-        self.entries.sort_by(|a, b| a.key.cmp(&b.key));
+        self.entries.sort_unstable_by(|a, b| a.key.cmp(&b.key));
         (&self.entries, self.total_key_size, self.total_value_size)
     }
 

turbopack/crates/turbo-persistence/src/write_batch.rs

@@ -291,7 +291,7 @@ impl<K: StoreKey + Send + Sync, const FAMILIES: usize> WriteBatch<K, FAMILIES> {
 
         shared_error.into_inner()?;
         let seq = self.current_sequence_number.load(Ordering::SeqCst);
-        new_sst_files.sort_by_key(|(seq, _)| *seq);
+        new_sst_files.sort_unstable_by_key(|(seq, _)| *seq);
         Ok(FinishResult {
             sequence_number: seq,
             new_sst_files,