Show recent challenge contributors instead of random; bump PHP platform to 8.3 and update lockfile

- Replace inRandomOrder() with orderBy('challenge_user.created_at', 'desc') in HomeController and ChallengeRepository so avatars/submissions and challenge user lists show most-recent contributors consistently (works with cached home content).
- Add PHP 8.3.0 to composer.json "platform" and regenerate composer.lock to reflect dependency updates and platform-overrides.

Author: robertotcestari

app/Http/Controllers/HomeController.php

@@ -88,7 +88,7 @@ public function index()
                                         'users.is_admin'
                                     )
                                     ->whereNotNull('avatar_url')
-                                    ->inRandomOrder()
+                                    ->orderBy('challenge_user.created_at', 'desc')
                                     ->limit(5);
                             }, // nao ordena por usuário logado pois informaçoes estão cacheadas
                         ])

app/Services/ChallengeRepository.php

@@ -45,7 +45,7 @@ protected function challengeCardsBaseQuery($query, $currentUser)
                                 $currentUser->id,
                             ]);
                         })
-                        ->inRandomOrder()
+                        ->orderBy('challenge_user.created_at', 'desc')
                         ->limit(5);
                 },
             ]);

composer.json

@@ -92,6 +92,9 @@
         "optimize-autoloader": true,
         "preferred-install": "dist",
         "sort-packages": true,
+        "platform": {
+            "php": "8.3.0"
+        },
         "allow-plugins": {
             "pestphp/pest-plugin": true,
             "php-http/discovery": true