feat: remove dead code

[vatsalaggarwal]

No description provided.

[androiddrew]

@vatsalaggarwal you missed https://github.com/metavoiceio/metavoice-src/blob/main/fam/llm/mixins/__init__.py#L2 and broke the build.

: UserWarning: `torchaudio.backend.common.AudioMetaData` has been moved to `torchaudio.AudioMetaData`. Please update the import path.
  from torchaudio.backend.common import AudioMetaData
Traceback (most recent call last):
  File "/home/toor/experiments/metavoice-src/fam/llm/serving.py", line 19, in <module>
    from fam.llm.sample import (
  File "/home/toor/experiments/metavoice-src/fam/llm/sample.py", line 23, in <module>
    from fam.llm.model import GPT, GPTConfig
  File "/home/toor/experiments/metavoice-src/fam/llm/model.py", line 13, in <module>
    from fam.llm.mixins import CausalInferenceMixin, NonCausalInferenceMixin
  File "/home/toor/experiments/metavoice-src/fam/llm/mixins/__init__.py", line 2, in <module>
    from fam.llm.mixins.gpt2loading import GPT2LoadingMixin
ModuleNotFoundError: No module named 'fam.llm.mixins.gpt2loading'

[vatsalaggarwal]

sorry, thanks for that... should be fixed in #24