🧩 Summary

This PR updates the GitHub Actions CI workflow (.github/workflows/ci.yml) to add missing cache steps across all jobs (format, lint, test, and docs_build).
💡 The change ensures consistent virtual environment caching (.venv) for faster runs and improved dependency management.

⚙️ Impacted Features:

• 🧰 CI/CD pipeline
• ⚡ Workflow caching efficiency
• 📦 Developer setup consistency

🧪 How to Test

1. Trigger the CI workflow via push or PR.
2. Verify that all jobs reuse the .venv cache instead of reinstalling dependencies.
3. Observe reduced job setup time in the Actions log.

🖼️ Screenshots (if applicable)

N/A

✅ Checklist

• Lint fixes and unit testing done
• End to end task testing
• Documentation updated

📝 Notes

• Adds a consistent cache key pattern for Python 3.9 environments.
• Expected to reduce CI runtime by avoiding redundant Poetry installs.