Inner powder snow faces are now culled against solid blocks

Discovered while testing MC-278787.

The bug

As of 24w33a, the inner faces of powder snow are no longer rendered against solid blocks. This change, to my knowledge, was completely unannounced, even if I now prefer this behaviour due to being consistent with water and lava.

How to reproduce

1. Place powder snow next to a solid block
2. Look at the solid block while inside the powder snow

Expected results

The solid block would be occluded by the powder snow's inner faces.

Actual results

It isn't.

Further notes

Fixing this issue may introduce a lot of extra geometry to places with a lot of powder snow and decrease performance, and also introduce an inconsistency with how fluids behave with respect to internal textures.