Entities with knockback resistance can get knocked back using Punch

The bug

Trying to summon a villager that cannot be moved (with 1.0 velocity-resistance). When shot with an non enchanted bow, the villager won't move. But when shot with a punch bow, it will, depending on the strength of the enchantment.

How to reproduce

1. Get yourself a bow with the punch enchantment.

   /give @p bow{Enchantments:[{id:punch,lvl:2}]}
   

2. Summon a villager with Knockback resistance.

   /summon minecraft:villager ~ ~ ~ {Attributes:[{Name:generic.knockback_resistance,Base:1.0}]}
   

   → The villager took knockback