Brown Mooshroom's texture doesn't match other cows

Affected version: 25w09a, 25w09b, 25w10a, 1.21.5-pre1

Summary: Brown mooshrooms didn't get the new pixels around their patches on their bodies.

Steps to Reproduce: To reproduce, simply summon a brown mooshroom and look at its body texture.

Observed Results: The brown mooshroom has not been updated.

Expected Results: The brown mooshroom has the new pixels around its patches.