`invulnerable_time` never decreases for some entities

Despite the 26.3 Snapshot 6 changelog implying that invulnerable_time is restricted to LivingEntities, it can exist on all entities. However, on some, including cushions and end crystals, the value will never decrease.

To reproduce:

1. Ensure ticks are not frozen

2. /summon armor_stand ~ ~ ~ {invulnerable_time:999}

3. /data get entity @n[type=minecraft:armor_stand] invulnerable_time
   ✅ The value has decreased by the number of ticks which elapsed in between you running the two commands

4. /summon cushion ~ ~ ~ {invulnerable_time:999}

5. /data get entity @n[type=minecraft:cushion] invulnerable_time
   ❌ The value remains the same