Update KV estimation example to match new code

[runger1101001]

https://github.com/simplefoc/Arduino-FOC/blob/e891cd7f5e46884b06633b5f2633c4f266baa4d1/examples/utils/calibration/find_kv_rating/encoder/find_kv_rating/find_kv_rating.ino#L39

Factor sqrt(3) is missing there (motor.target * sqrt(3)) Since the voltage in dq domain is like a phase zero value, but kv is phase phase. So it now overestimates by a factor 1.73