Beyond The End - Optimization and Fixes

Heal bosses to full health when they kill a player

Bosses kept the health they had left after killing a player, so players
could come back again and again and wear them down until they died. Now a
boss that kills a player goes back to full health.

A boss is any entity with its own boss bar (an instance field whose type
extends BossEvent, checked once per class: vanilla Wither, Twilight
Forest, Cataclysm, Meet Your Fight, Alex's Mobs, Mutant More, Dungeons
Mobs...), any boss from the Better Boss Bars config and the new
bte_optimization_fixes:bosses entity tag, extendable by datapack. The tag
holds the bosses whose bar lives outside the entity (Ender Dragon, Beyond
The End's Fallen Dragon and Jellyfish) and the ones that only Better Boss
Bars marks (Warden, Warped Mosco, Ender Golem): Better Boss Bars loads its
boss list in client setup only, so it is empty on dedicated servers.

The killer is the damage attacker (projectiles, spells and body parts
resolve to the boss) or, for deaths like falling or the void right after
a hit, the combat tracker's kill credit. Deaths prevented by a totem do
not count.