Snowy grass blocks near lava pools can generate without snow above them

The Bug:

Snowy grass blocks near lava pools can generate without snow above them.

Here is an example:

Version: 1.20.4

Seed: -5487380783244316696
Coordinates: /execute in minecraft:overworld run tp @s -1371.26 70.00 -1895.58 125.55 45.30

Steps to Reproduce:

1. Generate a world with the seed provided above and teleport to the given coordinates.

2. Look closely at the snowy grass block near the lava pool.

3. Take note as to whether or not snowy grass blocks near lava pools can generate without snow above them.

Observed Behavior:

Snowy grass blocks can generate without snow above them.

Expected Behavior:

Snowy grass blocks would not be able to generate without snow above them.