[Bugfix] Misaligned params in TreeAttentionImpl

[DarkLight1337]

Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Purpose

Tree attention is still broken because it conflicts with #21217 causing misaligned args to be passed to the model (notably attn_type becomes None). This PR fixes it.

cc @TheEpicDolphin

Test Plan

Test Result

(Optional) Documentation Update

[gemini-code-assist]

Code Review

This pull request addresses a bug in TreeAttentionImpl caused by a mismatched parameter blocksparse_params in its __init__ method. The change correctly removes this parameter and its corresponding check, resolving the argument conflict. The associated removal of an unused Any import is also a good cleanup. The fix is straightforward and correct.

[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.

🚀