fix(can): 캔 서비스 조회 트랜잭션을 적용한다

src/main/kotlin/kr/co/vividnext/sodalive/can/CanService.kt

@@ -6,10 +6,12 @@ import kr.co.vividnext.sodalive.common.CountryContext
 import kr.co.vividnext.sodalive.member.Member
 import org.springframework.data.domain.Pageable
 import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
 import java.time.ZoneId
 import java.time.format.DateTimeFormatter
 
 @Service
+@Transactional(readOnly = true)
 class CanService(
     private val repository: CanRepository,
     private val countryContext: CountryContext