Fix FP8 quantizer for Transformers v4

[yiliu30]

Description

Please briefly describe your main changes, the motivation.

Type of Change

• Bug fix
• New feature
• Documentation update
• Performance improvement
• Code refactoring
• Other (please specify):

Related Issues

Fixes or relates to #

Checklist Before Submitting

• My code has been tested locally.
• Documentation has been updated as needed.
• New or updated tests are included where applicable.

[Copilot]

Pull request overview

This PR aims to restore/fix FP8 fine-grained integration compatibility with Transformers v4 by switching the HPU finegrained-fp8 monkeypatch to a version-specific patch module, and by introducing a dedicated v4 patch implementation.

Changes:

• Update HPU patching to select a Transformers v4 vs v5+ compatible finegrained_fp8 replacement module at runtime.
• Add a new finegrained_fp8_patch_v4.py module providing FP8Linear replacement logic for Transformers v4.
• Add an example script for running FP8 static quantization and saving output.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 10 comments.

File	Description
examples/quant_model.py	Adds an example CLI for quantizing/saving a model with AutoRound FP8 static scheme.
auto_round/modeling/hpu_patch.py	Selects the correct finegrained_fp8 patch module depending on Transformers major version.
auto_round/modeling/finegrained_fp8_patch_v4.py	Introduces a Transformers v4-specific FP8Linear replacement implementation.

[a32543254]

LGTM