Apply suggestions from code review

Co-authored-by: Volkan Yazıcı <[email protected]>

Author: ppkarwasz

log4j-core/src/main/java/org/apache/logging/log4j/core/config/DefaultLayout.java

@@ -30,6 +30,8 @@
  *   This layout allows to create applications that don't contain {@link org.apache.logging.log4j.core.layout.PatternLayout}
  *   and all its patterns, e.g. GraalVM applications.
  * </p>
+ *
+ * @since 2.25.0
  */
 final class DefaultLayout implements StringLayout {