Remove usage of drain_filter (#30742)

This is a step on the way toward supporting stable rust.

components/script/dom/eventtarget.rs

@@ -448,7 +448,7 @@ impl EventTarget {
 
         let listener = EventListenerType::Additive(listener.clone());
         if let Some(entries) = handlers.get_mut(ty) {
-            entries.drain_filter(|e| e.listener == listener && e.once);
+            entries.retain(|e| e.listener != listener || !e.once)
         }
     }