[test] 영상용 대기열 인원 1명으로 변경

Author: TheGreatKang

backend/src/main/java/com/WEB4_5_GPT_BE/unihub/domain/enrollment/service/EnrollmentQueueService.java

@@ -18,7 +18,7 @@ public class EnrollmentQueueService {
 
     private static final String WAITING_QUEUE_KEY = "enrollment:waiting-queue";
     private static final String SESSION_PREFIX = "enrollment:session:";
-    private static final int MAX_CONCURRENT_USERS = 3;
+    private static final int MAX_CONCURRENT_USERS = 1;
     private static final Duration SESSION_TIMEOUT = Duration.ofMinutes(10);
     private final StringRedisTemplate redisTemplate;