Flickering custom item model

Discovered while testing https://github.com/CaffeineMC/sodium/issues/2943

The bug

Some custom translucent item models will flicker distractingly in-game, especially when in motion. This could pose an accessibility issue.

How to reproduce

1. Download and apply the attached resource pack
2. Get red stained glass
3. Observe its item form: dropped, framed, held, ...

Expected results

No flickering.

Actual results

There is.

How to fix

Make it not flicker.