[fix] make sure the pendingAddOps.remove() and pendingAddOps.peek() process the same element

Author: graysonzeng

bookkeeper-server/src/main/java/org/apache/bookkeeper/client/LedgerHandle.java

@@ -1836,7 +1836,11 @@ void sendAddSuccessCallbacks() {
                 return;
             }
 
-            pendingAddOps.remove();
+            if (!pendingAddOps.remove(pendingAddOp)) {
+                // If the remove operation fails, it means the element has already been removed by another thread.
+                // We should continue to the next iteration to process the next element.
+                continue;
+            }
             explicitLacFlushPolicy.updatePiggyBackedLac(lastAddConfirmed);
             pendingAddsSequenceHead = pendingAddOp.entryId;
             if (!writeFlags.contains(WriteFlag.DEFERRED_SYNC)) {