fix(curriculum): add validation test for filteredBooks release year (freeCodeCamp#64228)

Author: kannan-ravi

curriculum/challenges/english/blocks/lab-book-organizer/67172b43f84bcd2dec238a3d.md

@@ -89,6 +89,28 @@ assert.isBelow(filteredBooks.length, books.length)
 assert.isNotEmpty(filteredBooks)
 ```
 
+The `filteredBooks` array should only contain books from the original `books` array.
+
+```js
+filteredBooks.forEach(book => {
+  assert.isTrue(
+    books.some(original => 
+      original.title === book.title &&
+      original.authorName === book.authorName &&
+      original.releaseYear === book.releaseYear
+    )
+  );
+});
+```
+
+The `filteredBooks` array should include only books released on or before a specified year.
+
+```js
+const maxYear = Math.max(...filteredBooks.map(book => book.releaseYear));
+const removedYears = books.filter(book => !filteredBooks.includes(book)).map(book => book.releaseYear);
+assert.isTrue(removedYears.every(year => year > maxYear));
+```
+
 You should call the `sort` higher order function by passing the `sortByYear` callback function on the `filteredBooks` array.
 
 ```js