Update Homebrew formula to 0.3.0

[ictechgy]

Summary

• update the canonical Homebrew formula to the published weightclass 0.3.0 sdist
• use PyPI's hashed source URL and verified SHA-256

Verification

• v0.3.0 Release workflow completed successfully, including strict Twine metadata and Trusted Publishing
• PyPI JSON reports weightclass 0.3.0
• clean temporary venv install reports weightclass 0.3.0 and preserves low/high default classify output
• downloaded sdist SHA-256 matches the formula
• Ruby syntax check passed

After merge, the canonical formula will be copied to ictechgy/homebrew-tap and verified inside the tap with brew style, brew audit, source install, and brew test.