chore: logger category fix (ogx-ai#3706)

# What does this PR do?
WARNING 2025-10-06 12:01:45,137 root:266 uncategorized: Unknown logging
category: tokenizer_utils. Falling back to default 'root' level: 20

## Test Plan

Author: ehhuang

llama_stack/models/llama/tokenizer_utils.py

@@ -9,7 +9,7 @@
 
 from llama_stack.log import get_logger
 
-logger = get_logger(__name__, "tokenizer_utils")
+logger = get_logger(__name__, "models")
 
 
 def load_bpe_file(model_path: Path) -> dict[bytes, int]: