[wip] test: add coverage for all cli commands

[sricketts]

📌 Description

For #1833 - adds coverage for all CLI commands in flashinfer/__main__.py.

🔍 Related Issues

🚀 Pull Request Checklist

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✅ Pre-commit Checks

• I have installed pre-commit by running pip install pre-commit (or used your preferred method).
• I have installed the hooks with pre-commit install.
• I have run the hooks manually with pre-commit run --all-files and fixed any reported issues.

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🧪 Tests

• Tests have been added or updated as needed.
• All tests are passing (unittest, etc.).

Reviewer Notes

Do we want all tests in a single file or split by command?

[sricketts]

Main remaining items:

• Fix module-status test (currently hitting error during module registration)
• Maybe: add additional module tests as listed by TODO items in the code (or we can leave these for follow up PRs)
• Get these tests added to internal and public CI