fix(autoware_motion_velocity_obstacle_velocity_limiter_module): fix unreadVariable warning (#7625)

Signed-off-by: Ryuta Kambe <ryuta.kambe@tier4.jp>

Author: veqcc

planning/motion_velocity_planner/autoware_motion_velocity_obstacle_velocity_limiter_module/src/trajectory_preprocessing.cpp

@@ -68,15 +68,13 @@ TrajectoryPoints downsampleTrajectory(
 
 void calculateSteeringAngles(TrajectoryPoints & trajectory, const double wheel_base)
 {
-  auto t = 0.0;
   auto prev_point = trajectory.front();
   auto prev_heading = tf2::getYaw(prev_point.pose.orientation);
   for (auto i = 1ul; i < trajectory.size(); ++i) {
     const auto & prev_point = trajectory[i - 1];
     auto & point = trajectory[i];
     const auto dt = autoware::universe_utils::calcDistance2d(prev_point, point) /
                     prev_point.longitudinal_velocity_mps;
-    t += dt;
     const auto heading = tf2::getYaw(point.pose.orientation);
     const auto d_heading = heading - prev_heading;
     prev_heading = heading;