MicroRos does not publish imu data in higher rates

## Issue template

- I am working on ESP32 WROOM 32
- RTOS: It is running on (PC) linux ubuntu 20.04.6 LTS via
- Installation type: Arduino micro_ros_arduino library
- Version or commit hash: ROS2 galactic

#### Steps to reproduce the issue
I am using "Bolder Flight Systems MPU9250" library to read MPU9250 imu data. I created a imu publisher and message type was sensor_msgs/msg/imu. The sensor normally can run in 200 hz rate. I configured the timer callback for 200 hz, so timer_timeout was 5 ms and I used RCL_MS_TO_NS function to convert it nanoseconds. I used "rclc_publisher_init_best_effort" while creating the publisher and it spinned 1ms via "RCSOFTCHECK(rclc_executor_spin_some(&executor, RCL_MS_TO_NS(1)))". I updated the imu data and assigned imu data to imu publisher messages in the timer callback. I also published in the timer callback.

#### Expected behavior
I expected 200 hz publisher rate.

#### Actual behavior
It is published in approximately 34 Hz when i checked with "ros2 topic hz /imu_data"

#### Additional information

Start by reproducing the issue with the Arduino micro_ros_arduino library on an ESP32 WROOM 32, using the rclc timer callback, rclc_publisher_init_best_effort, and rclc_executor_spin_some calls described. Measure /imu_data with ros2 topic hz and compare the result with the configured 200 Hz timer; done means the cause of the approximately 34 Hz rate is identified and the expected rate is reached or documented.

Written by the indexing model from the issue text.