fix: Redis HSET String Serializer 설정

Author: dlsrks1021

backend/src/main/java/io/f1/backend/global/config/RedisConfig.java

@@ -24,6 +24,8 @@ public RedisTemplate<String, Object> redisTemplate(
         RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
         redisTemplate.setConnectionFactory(redisConnectionFactory);
         redisTemplate.setKeySerializer(new StringRedisSerializer());
+        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
+        redisTemplate.setHashValueSerializer(new StringRedisSerializer());
         redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
 
         redisConnectionFactory.getConnection().serverCommands().flushAll();