8317873: Add @sealedGraph to IllegalFormatException

Reviewed-by: naoto, iris

src/java.base/share/classes/java/util/IllegalFormatException.java

@@ -31,6 +31,7 @@ package java.util;
  * explicit subtypes of this exception which correspond to specific errors
  * should be instantiated.
  *
+ * @sealedGraph
  * @since 1.5
  */
 public sealed class IllegalFormatException extends IllegalArgumentException