test: Enable test_text_chat_completion_with_tool_choice_required for remote::vllm

[terrytangyuan]

What does this PR do?

This verifies that #1059 test passed for remote::vllm so I am removing the xfail here.

Test Plan

Test passed:

LLAMA_STACK_BASE_URL=http://localhost:5002 pytest -v tests/client-sdk/inference/test_text_inference.py::test_text_chat_completion_with_tool_choice_required 
=============================================================== test session starts ===============================================================
platform linux -- Python 3.10.16, pytest-8.3.4, pluggy-1.5.0 -- /home/yutang/.conda/envs/distribution-myenv/bin/python3.10
cachedir: .pytest_cache
rootdir: /home/yutang/repos/llama-stack
configfile: pyproject.toml
plugins: anyio-4.8.0
collected 1 item                                                                                                                                  

tests/client-sdk/inference/test_text_inference.py::test_text_chat_completion_with_tool_choice_required[meta-llama/Llama-3.1-8B-Instruct] PASSED [100%]

[ehhuang]

Thanks!