fix: removes unnecessary book not found exception throws clause

Author: DevDario

src/main/java/ao/com/academy/libraryapi/services/BookService.java

@@ -14,7 +14,7 @@ public class BookService {
     @Autowired
     BookRepository bookRepository;
 
-    public List<BookDTO> getBooks() throws BookNotFoundException{
+    public List<BookDTO> getBooks(){
         return bookRepository.findAll();
     }