Fix missing libzstd.so.1 when using torch 2.5.1+rocm6.1

[dnswd]

I use this flake to run ComfyUI with my AMD GPU, requiring the ROCm version of PyTorch (currently 2.5.1+rocm6.1) as outlined in the README. Running ComfyUI with this setup will produce the following error:

(venv)
[halcyon@ikigai:~/ai/ComfyUI]$ HSA_OVERRIDE_GFX_VERSION=10.3.0 python main.py
Traceback (most recent call last):
  File "/home/halcyon/ai/ComfyUI/main.py", line 88, in <module>
    import comfy.utils
  File "/home/halcyon/ai/ComfyUI/comfy/utils.py", line 20, in <module>
    import torch
  File "/home/halcyon/ai/ComfyUI/venv/lib/python3.10/site-packages/torch/__init__.py", line 367, in <module>
    from torch._C import *  # noqa: F403
ImportError: libzstd.so.1: cannot open shared object file: No such file or directory

ComfyUI works fine after adding zstd to the NIX_LD_LIBRARY_PATH.

Edit: Image proof