[wpimath] Fix SimpleMotorFeedforward no-accel overload returning negative voltage outputs (#7999)

SimpleMotorFeedforward::calculate(velocity) was not updated to account for the removal of calculate(velocity, acceleration), so it would pass currentVelocity = velocity and nextVelocity = 0, resulting in negative outputs in many scenarios.

wpimath/src/main/java/edu/wpi/first/math/controller/SimpleMotorFeedforward.java

@@ -157,7 +157,7 @@ public class SimpleMotorFeedforward implements ProtobufSerializable, StructSeria
    * @return The computed feedforward.
    */
   public double calculate(double velocity) {
-    return calculate(velocity, 0);
+    return calculate(velocity, velocity);
   }
 
   /**