use unstable sort

crates/bevy_sprite/src/render/mod.rs

@@ -322,7 +322,7 @@ pub fn prepare_sprites(
 
     // sort first by z and then by handle. this ensures that, when possible, batches span multiple z layers
     // batches won't span z-layers if there is another batch between them
-    extracted_sprites.sprites.sort_by(|a, b| {
+    extracted_sprites.sprites.sort_unstable_by(|a, b| {
         match a.transform.w_axis[2].partial_cmp(&b.transform.w_axis[2]) {
             Some(Ordering::Equal) | None => a.handle.cmp(&b.handle),
             Some(other) => other,