Fix javadoc in RedisClusterClient

Author: uglide

src/main/java/redis/clients/jedis/RedisClusterClient.java

@@ -22,16 +22,13 @@
  * <p>
  * <b>Usage:</b>
  * 
- * <pre>
- * {
- *   &#64;code
+ * <pre>{@code
  *   Set<HostAndPort> clusterNodes = new HashSet<>();
  *   clusterNodes.add(new HostAndPort("127.0.0.1", 7000));
  *   RedisClusterClient client = new RedisClusterClient(clusterNodes);
  *   client.set("key", "value");
  *   String value = client.get("key");
- * }
- * </pre>
+ * }</pre>
  * <p>
  * <b>Migration:</b> Users of {@code JedisCluster} are encouraged to migrate to this class for
  * improved API consistency, better resource management, and enhanced support for future Redis