Bosch BNO055 gyroscope bias stability
I don't believe that there are any solid state gyros with this type of bias.  I think you will need an electromechanical device.  Consider that while sitting on the equator, a perfect gyro will report 15 degrees per hour from the earth spinning on its axis, so you are trying to sense rotation of this small magnitude.  Such gyros so exist but may cost thousands of dollars depending on the size (larger gyros are easier to build at this sensitivity.)  They are generally used in military aircraft, weapons or navigational applications.