[Misc] collect flashinfer version in collect_env.py

[yeqcharlotte]

Purpose

While working on repro in yeqcharlotte#3, notice flashinfer version is not collected 😂

Test Plan

python vllm/collect_env.py 

Test Result

https://gist.github.com/yeqcharlotte/edbbf13b07a3e26e05ef14519641ca6e

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Versions of relevant libraries
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[pip3] efficientnet_pytorch==0.7.1
[pip3] flashinfer-python==0.3.1

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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.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.

[gemini-code-assist]

Code Review

This pull request adds flashinfer-python to the list of packages whose versions are collected by collect_env.py. The change is straightforward and correct, adding the package name to both DEFAULT_CONDA_PATTERNS and DEFAULT_PIP_PATTERNS. This will ensure the flashinfer version is included in the environment report, which is useful for debugging. The implementation is correct and I have no suggestions for improvement.