[Tests] Remove cache_dir parameter from test fixture

The cache_dir parameter was removed from ModelArguments in favor of
environment variables. This commit updates the test fixture to no
longer pass cache_dir to AutoTokenizer.from_pretrained().

Fixes the AttributeError in test_dataset_loading.py and test_registry.py
tests that were failing in CI/CD.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>
Signed-off-by: Ralph Bean <[email protected]>

Author: ralphbean

tests/llmcompressor/transformers/finetune/data/conftest.py

@@ -18,7 +18,6 @@ def tiny_llama_model_args(tiny_llama_path):
 def tiny_llama_tokenizer(tiny_llama_model_args):
     tokenizer = AutoTokenizer.from_pretrained(
         tiny_llama_model_args.model,
-        cache_dir=tiny_llama_model_args.cache_dir,
         use_fast=True,
         revision=tiny_llama_model_args.model_revision,
         use_auth_token=True if tiny_llama_model_args.use_auth_token else None,