"Player and mob dithering" toggle does not affect non-attachable items

When you enabled "Player and mob dithering" toggle in Accessibility settings, and then hold non-attachable items (like Grass Block or Diamond Sword), the items will not get dithered.

Steps to reproduce:

1. Enable dithering for mobs and players: Settings > Accessibility > then enable "Player and mob dithering" toggle

2. Give yourself a Shield and a blocks or items

3. Put the Shield in your off-hand, and blocks or items in your main hand

4. Put some blocks in front of you, then change your perspective to 3rd person front

5. Observe

Expected results:
Non-attachable items get dithered, like attachable items and entity model does.

Observed results:
Non-attachable items does not get dithered.