Fix simulated gimbal behavior with zero velocity (#25217)

* fix simulated gimbal behavior with zero velocity

* check for PX4_ISFINITE before checking for magnitude

Author: teapfw

src/modules/simulation/gz_bridge/GZGimbal.cpp

@@ -240,6 +240,11 @@ float GZGimbal::computeJointSetpoint(const float att_stp, const float rate_stp,
 {
 
 	if (PX4_ISFINITE(rate_stp)) {
+		if (math::abs_t(rate_stp) < FLT_EPSILON) {
+			// Handle zero velocity by sending the last target angle
+			return last_stp;
+		}
+
 		const float rate_diff = dt * rate_stp;
 		const float stp_from_rate = last_stp + rate_diff;