Lecterns z-fight with the back faces of item frames

Discovered while testing MC-268047. Relates to MC-262686 and MC-262687.

The bug

If a lectern is placed inside of an item frame, and the item frame is viewed from behind, Z-fighting is visible.

How to fix

Perhaps cull the faces of items in item frames if they're coplanar with the back face (or between the front and back of the leather section of the frame inclusive)?