refactor:[kakao-tech-campus-2nd-step3#84]- ProductService

불필요한 어노테이션 변경

src/main/java/com/helpmeCookies/product/service/ProductService.java

@@ -36,8 +36,7 @@ public ProductPage.Paging getProductsByPage(String query, Pageable pageable) {
         return ProductPage.Paging.from(productPage);
     }
 
-    @Transactional
-    @GetMapping
+    @Transactional(readOnly = true)
     public ProductPage.Paging getProductsWithRandomPaging(Pageable pageable) {
         var productPage = productRepository.findAllRandom(pageable);
         return ProductPage.Paging.from(productPage);