chore: Java 스타일 수정

Author: github-actions

backend/src/main/java/io/f1/backend/domain/admin/api/AdminController.java

@@ -7,8 +7,6 @@
 import lombok.RequiredArgsConstructor;
 
 import org.springframework.data.domain.Pageable;
-import org.springframework.data.domain.Sort.Direction;
-import org.springframework.data.web.PageableDefault;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;