Fix Carbon3 diffInSeconds to use int and not float (spatie#500)

Author: it-can

src/Middlewares/CacheResponse.php

@@ -126,7 +126,7 @@ protected function getTags(array $args): array
     public function addCacheAgeHeader(Response $response): Response
     {
         if (config('responsecache.add_cache_age_header') and $time = $response->headers->get(config('responsecache.cache_time_header_name'))) {
-            $ageInSeconds = Carbon::parse($time)->diffInSeconds(Carbon::now());
+            $ageInSeconds = (int) Carbon::parse($time)->diffInSeconds(Carbon::now(), true);
 
             $response->headers->set(config('responsecache.cache_age_header_name'), $ageInSeconds);
         }