[Experimental] Grass Blocks Can Generate In Caves at Y40 and Above

Summary: Grass in Caves.

Steps To Reproduce:
Step 1: Strip Mine at Y40 in 1.17.30.23 With Caves n Cliffs Enabled.
Step 2: Repeat

Observed Result: Grass in Caves.

Expected Result: No Grass Should Be in Caves (Grass Blocks).