Install skip qigen(windows)

[qwopqwop200]

qigen currently does not support windows. Therefore, we made it so that qigen is not installed on Windows.

Currently, I can make Windows generate qigen's backend.cpp, but pytorch fails to compile backend.cpp.

[PanQiWei]

Hi @qwopqwop200 , thank you for the fixing, it looks good to me.

Here is one topic I want to futher discuss that we may do in another PR:

Can we treat Qigen as a third party package so that we can optionally depend on it when install autog-gptq like using pip install auto-gptq[qigen]. The reason is p = int(subprocess.run("cat /proc/cpuinfo | grep cores | head -1", shell=True, check=True, text=True, stdout=subprocess.PIPE).stdout.split(" ")[2])'s result is highly depend on the CPU what we have at hand, and if we pre-build the wheels, it may use a small value like 8, while our users may have an advanced CPU with 32 or even 64 cores.

[fxmarty]

Qiwen breaks the installation from source on Linux, see #333. AutoGPTQ not having a CI is kind of a big issue.