#186 fix : 사용하지 않는 import문 삭제

src/main/java/com/gongjakso/server/global/config/CacheConfig.java

@@ -5,13 +5,7 @@
 import org.springframework.cache.concurrent.ConcurrentMapCacheManager;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.data.redis.cache.RedisCacheConfiguration;
-import org.springframework.data.redis.cache.RedisCacheManager;
-import org.springframework.data.redis.connection.RedisConnectionFactory;
-import org.springframework.data.redis.serializer.RedisSerializationContext;
-import org.springframework.data.redis.serializer.StringRedisSerializer;
 
-import java.time.Duration;
 
 @EnableCaching
 @Configuration