Jockeys use the mount's follow range for danger avoidance pathfinding

When a jockey mob is pathfinding to avoid dangerous blocks, it uses the follow_range value of the mount instead of the rider.

Steps to reproduce:

1. U-shaped path with magma block floor, Chicken jockey spawned in the center.

2. Chicken follow_range = 16, Zombie follow_range = 16 → Jockey stops at the edge of magma blocks and cannot find a safe path to the player.❌

3. Chicken follow_range = 16, Zombie follow_range = 40 → Jockey still stops at the edge and cannot find a safe path. ❌

4. Chicken follow_range = 40, Zombie follow_range = 16 → Jockey successfully navigates around magma. ✅

This clearly proves the pathfinding check uses the mount’s follow_range, not the rider’s.