feat: support training with JSON string tool arguments (#3136)

* feat: support training with JSON string tool arguments; fix PyArrow data type inconsistent error

* feat: raise error for tool call arguments decode

* Add test_chat_templates_tool_call_string_arguments.py

Add test for string arguments

* fix: change to correct qwen3 tokenizer

* fix: update docs to clarify arguments json

* chore: lint

* fix: duplicate

* chore: revert

* feat: add error to faq

* fix: remove duplicate fixture

---------

Co-authored-by: caoqinping <caoqinping@lixiang.com>
Co-authored-by: gamersover-blog <1611885128@qq.com>
Co-authored-by: NanoCode012 <nano@axolotl.ai>

tests/prompt_strategies/test_chat_templates_thinking.py

@@ -4,7 +4,6 @@ Tests for splitting reasoning/thinking from content into separate field
 
 import pytest
 from datasets import Dataset
-from transformers import AutoTokenizer
 
 from axolotl.prompt_strategies.chat_template import (
     load,
@@ -56,15 +55,6 @@ def messages_w_reasoning_fixture():
     )
 
 
-@pytest.fixture(name="qwen3_tokenizer")
-def qwen3_tokenizer_fixture(
-    download_qwen3_half_billion_model,
-):
-    tokenizer = AutoTokenizer.from_pretrained("Qwen/Qwen3-0.6B")
-
-    return tokenizer
-
-
 class TestSplitThinking:
     """
     test class to make sure datasets with reasoning content conforms to the chat_template strategy