[Minor] Auto Target Fix - Prioritize checking if the target is dead

[Fly-Star-him]

Units that have already died enter auto-target checking, which can cause some issues, so try to fix them.
已经死亡的单位会进入自动索敌检查，它们可能会造成一些问题，因此尝试修复。

[github-actions]

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[CrimRecya]

I think this is an invalid fix. All places where this function is called have already used the pTarget pointer to call virtual functions. So if this issue cannot be solved from the root, then it cannot be placed here either. You should make these sanity check before calling IsAlliedWith which has called GetOwningHouse.
Moreover, I think that this fix will affect the performance of the enemy searching and will not occur frequently. A switch should be set to disabled this fix by applying patch.

[Fly-Star-him]

They were always here. All I did was rearrange them to prevent accidents.

[CrimRecya]

It looks fine now, but I still hope it can be turned off by Patch::Apply_RAW like DisableRadDamageOnBuildings, as in most cases these hooks are not needed.