With the changes in this PR, weapon explosions only do the collision check once, in AddWeaponExplosion(). I set the dontDeleteOnCollision flag to prevent the missile from immediately deleting itself. This means the missile animation will always play to completion regardless of whether the elemental damage strikes the target.

I modified DoAttack() to use the didhit flag to determine whether the missile should attempt to do damage to the target. Just like with elemental arrows, if the physical attack doesn't hit, the elemental attack doesn't hit either. In order to skip the collision check but still play the missile animation, DoAttack() simply sets the missile damage to zero if the physical attack missed. AddWeaponExplosion() will skip the collision check entirely if it sees that the missile damage is zero.

This resolves #7571