Remove missing weights silencers in favor of HFQuantizer solution

[kylesayrs]

Purpose

• Remove warning silencing code that was previously needed for loading quantized models but is now handled by Improve model loading for compressed tensor models huggingface/transformers#36152

[github-actions]

👋 Hi! Thank you for contributing to llm-compressor. Please add the ready label when the PR is ready for review.

[kylesayrs]

This PR used to implement a skip_missing_weights_context, which silenced warnings about missing weights when loading a quantized model. Instead, @rahul-tuli will implement a more integrated solution into HF quantizer which silences these warnings directly, and this PR becomes simply the removal of the old code we had to silence these warnings

[kylesayrs]

@rahul-tuli's HFQuantizer changes must land before this lands

[kylesayrs]

huggingface/transformers#36152 has landed

[rahul-tuli]

Thank you for this change!