Loom recipe buttons render translucent pixels as opaque

More loosely relates to these issues: MC-144009 MC-145821 MC-164001 MC-165403

The bug

If textures used for loom recipes contain translucent pixels, these incorrectly render as opaque in-game.

How to reproduce

1. Download and apply the attached resource pack
2. Put a banner and dye in a loom
3. Observe

Expected results

Translucent buttons.

Actual results

Opaque buttons.