refactor: 배포 환경에서 slow-query의 원인이 된 NOT EXIST -> LEFT JOIN 수정

service/src/main/kotlin/com/sangdol/roomescape/schedule/infrastructure/persistence/ScheduleRepository.kt

@@ -134,14 +134,14 @@ interface ScheduleRepository : JpaRepository<ScheduleEntity, Long> {
             s.id
         FROM
             schedule s
+        LEFT JOIN 
+            reservation r
+        ON 
+            r.schedule_id = s.id AND r.status IN ('PENDING', 'PAYMENT_IN_PROGRESS')
         WHERE 
             s.status = 'HOLD'
             AND s.hold_expired_at <= :now
-            AND NOT EXISTS (
+            AND r.id IS NULL
-                SELECT 1
-                FROM reservation r
-                WHERE r.schedule_id = s.id AND (r.status = 'PENDING' OR r.status = 'PAYMENT_IN_PROGRESS')
-            )
         FOR UPDATE SKIP LOCKED
         """, nativeQuery = true
     )