Fix wrong inherited javadoc of AsyncFile#exceptionHandler (#5432)

See
https://vertx.io/docs/5.0.0.CR3/apidocs/io/vertx/core/file/AsyncFile.html#exceptionHandler(io.vertx.core.Handler)
The inherited javadoc say that it sets the exception handler on the read stream only.

Fix: Mention that is also sets it on the write stream.

vertx-core/src/main/java/io/vertx/core/file/AsyncFile.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2021 Contributors to the Eclipse Foundation
+ * Copyright (c) 2011-2025 Contributors to the Eclipse Foundation
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -21,7 +21,6 @@
 import io.vertx.core.streams.ReadStream;
 import io.vertx.core.streams.WriteStream;
 
-import java.util.function.Function;
 import java.util.function.Supplier;
 
 /**
@@ -55,6 +54,12 @@ public interface AsyncFile extends ReadStream<Buffer>, WriteStream<Buffer> {
   @Override
   AsyncFile drainHandler(Handler<Void> handler);
 
+  /**
+   * Set an exception handler on the read stream and on the write stream.
+   *
+   * @param handler the handler
+   * @return a reference to this, so the API can be used fluently
+   */
   @Override
   AsyncFile exceptionHandler(Handler<Throwable> handler);