Pigs' equipment is deleted when converting to zombified piglins

Since it was requested that MC-311623 be split up, this report covers equipment transfer when a pig converts to a zombified piglin.

When such a conversion occurs, the pig’s equipment is deleted. Per the standard outlined in MC-311623, it would be expected that the items a zombified piglin cannot make use of (body and saddle) would be dropped according to drop_chances (preferably reflecting the chance value exactly), while the remaining items (hands, armor) would be retained by the zombified piglin. However, for this particular conversion, there should be a unique interaction: a weapon for the zombified piglin (either a golden sword or golden spear) is selected, and if the piglin prefers it to the pig’s main-hand item, the latter is also dropped according to drop_chances instead of retained. (If the pig was holding a better weapon no golden sword or spear would be dropped.)

To reproduce

1. /summon minecraft:pig ~ ~ ~ {NoAI:1b,equipment:{saddle:{id:saddle}},drop_chances:{saddle:2f}}

2. /summon minecraft:lightning_bolt

3. /data get entity @n[type=minecraft:zombified_piglin] equipment
   ❌ The saddle has been deleted

Expected behavior

The saddle would be dropped on the ground (utilizing invulnerable_time to avoid the lightning damage).

Code analysis

Code analysis by YouTuber JASON13 can be found here: https://youtu.be/BBFaNYwZ8-o?si=NPhIG_gUQUwTnR4y&t=283