Fix Javadoc

This commit fixes various Javadoc issues across the code base.

See gh-32403

spring-web/src/main/java/org/springframework/http/server/reactive/AbstractListenerWriteProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -70,7 +70,7 @@ public abstract class AbstractListenerWriteProcessor<T> implements Processor<T,
 	 * Indicates we're waiting for one last isReady-onWritePossible cycle
 	 * after "onComplete" because some Servlet containers expect this to take
 	 * place prior to calling AsyncContext.complete().
-	 * See https://github.com/eclipse-ee4j/servlet-api/issues/273
+	 * @see <a href="https://github.com/eclipse-ee4j/servlet-api/issues/273">gh-273</a>
 	 */
 	private volatile boolean readyToCompleteAfterLastWrite;
 

spring-web/src/main/java/org/springframework/web/util/HtmlCharacterEntityReferences.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,7 +31,7 @@ import org.springframework.util.Assert;
  * HTML 4.0 standard.
  *
  * <p>A complete description of the HTML 4.0 character set can be found
- * at https://www.w3.org/TR/html4/charset.html.
+ * at <a href="https://www.w3.org/TR/html4/charset.html">https://www.w3.org/TR/html4/charset.html</a>.
  *
  * @author Juergen Hoeller
  * @author Martin Kersten