Holding items enchanted with thorns in your hand works as if you were wearing them

The Bug:

Holding items enchanted with thorns in your hand works as if you were wearing them.

Steps to Reproduce:

1. Switch into survival mode and hold an item enchanted with thorns by using the command provided below.

   /item replace entity @s weapon.mainhand with minecraft:golden_helmet{Enchantments:[{id:"minecraft:thorns",lvl:3}]}

2. Summon an entity that will attack you, for example, a husk.
3. Let it damage you a couple of times.
4. Take note as to whether or not holding items enchanted with thorns in your hand works as if you were wearing them.

Observed Behavior:

Holding items enchanted with thorns in your hand works as if you were wearing them.

Expected Behavior:

Holding items enchanted with thorns in your hand would not work as if you were wearing them.

Code Analysis:

Code analysis by Marcono1234 can be found in this comment.