Revert "[https://nvbugs/6050483][fix] Cap diffusers<0.38.0 in requirements.txt"

This reverts commit c53cf45.

Author: chang-l

requirements.txt

@@ -4,7 +4,7 @@ accelerate>=1.7.0
 build
 colored
 cuda-python>=13
-diffusers>=0.27.0,<0.38.0  # cap: huggingface/diffusers#13356 breaks UniPCMultistepScheduler on GPU
+diffusers>=0.27.0
 lark
 mpi4py
 numpy>=2.0.0,<2.4 # numba 0.63.1 requires numpy<2.4