Grass blocks in dark forests no longer have a side overlay if Biome Blend is disabled

When Biome Blend is set to 0, the side texture of grass blocks in Dark Forests only displays grass_block_side.png without the overlay grass_block_side_overlay.png.

Steps to reproduce:

• Go to Video Settings and set Biome Blend to 0

• Locate a Dark Forest with /locate biome and teleport there

Expected result:

• The side texture of grass blocks in the Dark Forest has the grass overlay.

Actual result:

• The side texture of grass blocks in the Dark Forests doesn’t have the grass overlay.