Light is bleeding through with smooth lighting enabled

[etherested]

Request Description

Looks like SmoothLightPipeline doesn't fix the issue

Steps to reproduce:

1. Install Sodium on NeoForge 1.21.1/1.21.11 (latest)
2. Build a roof out of stairs
3. Observe

Mojira ticket: https://bugs.mojang.com/browse/MC/issues/MC-12558