[Misc] Add support for new autogptq checkpoint_format

[Qubitium]

Reason for PR: make sure loading of gptq marlin quants is compatible with latest autogptq

Due to autogpq update AutoGPTQ/AutoGPTQ#603 quants made with autogptq >=0.8.0-dev will use a new checkpoint_format property to hold marlin and future formats.

Compat tested with both marlin and non-marlin in both old is_marlin_format and new checkpoint_format

[robertgshaw2-neuralmagic]

Thanks, will review this

[robertgshaw2-neuralmagic]

Do you have examples models in each format I can try?

[Qubitium]

@robertgshaw2-neuralmagic

1. Marlin: https://huggingface.co/LnL-AI/TinyLlama-1.1B-Chat-v1.0-GPTQ-Marlin-4bit
2. Non-Marlin: https://huggingface.co/LnL-AI/TinyLlama-1.1B-Chat-v1.0-GPTQ-4bit

To test marlin compat just change the quntize_config param:

"checkpoint_format": "marlin" => "is_marlin_format": true

[robertgshaw2-neuralmagic]

Each of the following works:

• new serialization config

from vllm import LLM
model = LLM("LnL-AI/TinyLlama-1.1B-Chat-v1.0-GPTQ-Marlin-4bit")
model.generate("hello my name is")

• old serialization config

from vllm import LLM
odel = LLM("neuralmagic/TinyLlama-1.1B-Chat-v1.0-marlin")
model.generate("hello my name is")

[robertgshaw2-neuralmagic]

@Qubitium Can you merge the PR I posted to your branch, which adds tests for this case?

Qubitium#1

[Qubitium]

@robertgshaw2-neuralmagic merged

[robertgshaw2-neuralmagic]

@Qubitium can you rerun ./format.sh? Will merge after

[robertgshaw2-neuralmagic]

nvm saw you commit. Letting CI run then will merge