Revert "[HUDI-3043] Revert async cleaner leak commit to unblock CI failure (#4343)" (#4465)

This reverts commit 7e7ad1558c.

hudi-flink/src/main/java/org/apache/hudi/sink/CleanFunction.java

@@ -98,4 +98,11 @@ public class CleanFunction<T> extends AbstractRichFunction
   public void initializeState(FunctionInitializationContext context) throws Exception {
     // no operation
   }
+
+  @Override
+  public void close() throws Exception {
+    if (this.writeClient != null) {
+      this.writeClient.close();
+    }
+  }
 }