Mobs with Health Boost reset health after relog

Mobs will lose all extra hearts gained while they have health boost when the player reloads the world.

Steps to Reproduce:
1. Spawn a mob
2. Effect them with a high level of health boost using commands
3. Throw lots of healing potions on the mob
4. Hit with a netherite sword (notice it doesn't die)
5. Leave and rejoin the world
6. Hit with a sword again

Observed Results:
The mob keeps the health boost effect, but its health gets reset back to default

Expected Results:
The mob keeps the same amount of extra hearts it was healed before relog.