diaryreqs: Update scrollbar with new length

This interface was ported to a different widget (in #5346), but that interface has a dynamic length, controlled by cs2 2523, which is called by the server when the interface is filled. Simply call the cs2 again after the next one has ran with our new linecount.

runelite-api/src/main/java/net/runelite/api/ScriptID.java

@@ -54,6 +54,15 @@ public final class ScriptID
 	 */
 	public static final int CLOSE_CHATBOX_INPUT = 299;
 
+	/**
+	 * Updates the Diary/Quest interface's scrollbar
+	 * <ul>
+	 * <li> int (boolean) Reset scroll position </li>
+	 * <li> int Number of lines </li>
+	 * </ul>
+	 */
+	public static final int DIARY_QUEST_UPDATE_LINECOUNT = 2523;
+
 	/**
 	 * Initializes the chatbox input to use RuneLite callbacks
 	 * <ul>