Use absolute imports

[bndos]

• Switch to absolute imports to ensure vptq.ops is correctly located on a local setup.
• Allow running vptq as a script without requiring the -m flag.
• Resolve Issue CUDA Kernel Not Found: Fallback to Torch Implementation During vptq Execution in Local Setup #89 where CUDA kernel is not found in local setups.

[bndos]

@bndos please read the following Contributor License Agreement(CLA). If you agree with the CLA, please reply with the following information.

@microsoft-github-policy-service agree [company="{your company}"]

Options:

• (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@microsoft-github-policy-service agree

• (when company given) I am making Submissions in the course of work for my employer (or my employer has intellectual property rights in my Submissions by contract or applicable law). I have permission from my employer to make Submissions and enter into this Agreement on behalf of my employer. By signing below, the defined term “You” includes me and my employer.

@microsoft-github-policy-service agree company="Microsoft"

Contributor License Agreement

@microsoft-github-policy-service agree

[wejoncy]

Hi @bndos very thanks for you contribution.

LGTM.
Could you format the code to pass the CI before we can get it merged?

[YangWang92]

Hi @bndos,
Thank you for your contribution. I noticed that there was a problem with our formatter settings, and I've just fixed it. Thank you very much for your help! I have merged it into the main branch.