How dual gyroscopes can be used to remove gyro drift?
While you can fuse the measurements from multiple IMUs on a rigid body to get diminishing returns on state-estimation, there is no way to cancel out the gyro drift doing this alone. Integrating angular velocity to estimate yaw is fraught and yaw estimates will deteriorate within seconds.

Briefly, you can correct for gyro drift by fusing with yaw measurements from a magnetometer. Kalman filter based approaches do this by including the gyro-bias as states to be estimated. What you get is known as an Attitude and Heading Reference System (AHRS). One method for doing this is with the Madgwick Filter - if you're fooling around with Arduino by chance, there are numerous examples/demos online.