[Fix] Move "model_config" as keyword args in chat_utils.py

[lk-chen]

In #17805, trust_remote_code was removed, and model_config was added as first argument. It broke ray-project/ray#52975.

Now other python code that relies on chat_utils.py need to:

resolve_format_kwargs = dict(
  ...
  model_config=model_config,
)
try:
    resolved = resolve_chat_template_content_format(**resolve_format_kwargs)
except TypeError:
    # resolve_chat_template_content_format changed API in 0.9.0, older version doesn't expect `model_config`
    resolve_format_kwargs.pop("model_config")
    resolve_format_kwargs["trust_remote_code"] = model_config.trust_remote_code
    resolved = resolve_chat_template_content_format(**resolve_format_kwargs)

[github-actions]

👋 Hi! Thank you for contributing to the vLLM project.

💬 Join our developer Slack at https://slack.vllm.ai to discuss your PR in #pr-reviews, coordinate on features in #feat- channels, or join special interest groups in #sig- channels.

Just a reminder: PRs would not trigger full CI run by default. Instead, it would only run fastcheck CI which starts running only a small and essential subset of CI tests to quickly catch errors. You can run other CI tests on top of those by going to your fastcheck build on Buildkite UI (linked in the PR checks section) and unblock them. If you do not have permission to unblock, ping simon-mo or khluu to add you in our Buildkite org.

Once the PR is approved and ready to go, your PR reviewer(s) can run CI to test the changes comprehensively before merging.

To run CI, PR reviewers can either: Add ready label to the PR or enable auto-merge.

🚀

[DarkLight1337]

Otherwise LGTM. Sorry for breaking your code, didn't realize this is actively being used downstream, since it's not part of the official API.