chore: dataset의 불필요 필드 제거

Author: dlsrks1021

backend/src/test/resources/datasets/stat.yml

@@ -4,21 +4,15 @@ stat:
     total_games: 100
     winning_games: 100
     score: 1000
-    updated_at: 2025-07-17 10:00:00
-    created_at: 2025-07-17 10:00:00
 
   - id: 2
     user_id: 2
     total_games: 20
     winning_games: 20
     score: 200
-    updated_at: 2025-07-17 10:00:00
-    created_at: 2025-07-17 10:00:00
 
   - id: 3
     user_id: 3
     total_games: 30
     winning_games: 30
-    score: 300
-    updated_at: 2025-07-17 10:00:00
-    created_at: 2025-07-17 10:00:00
+    score: 300

backend/src/test/resources/datasets/user.yml

@@ -4,21 +4,15 @@ user_test:
     provider: "kakao"
     provider_id: "kakao1"
     last_login: 2025-07-17 10:00:00
-    created_at: 2025-07-17 10:00:00
-    updated_at: 2025-07-17 10:00:00
 
   - id: 2
     nickname: "USER2"
     provider: "kakao"
     provider_id: "kakao2"
     last_login: 2025-07-17 10:00:00
-    created_at: 2025-07-17 10:00:00
-    updated_at: 2025-07-17 10:00:00
 
   - id: 3
     nickname: "USER3"
     provider: "kakao"
     provider_id: "kakao3"
-    last_login: 2025-07-17 10:00:00
-    created_at: 2025-07-17 10:00:00
-    updated_at: 2025-07-17 10:00:00
+    last_login: 2025-07-17 10:00:00