fix: GPT OSS Conversion Script Enhancements (#42901)
* fix: Remove instruct as it should always be true and correct num_experts
* docs: improve docstring
* fix: remove unused argument
* fix: Only add extra special tokens if they exist
* fix: prefer .jinja extension for chat template
* fix: write raw, not json
Signed-off-by: Kyle Mylonakis <kyle@protopia.ai>
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Signed-off-by: Kyle Mylonakis <kyle@protopia.ai>
