CLI: Improve client cleanup in Makefile

[MonkeyCanCode]

The existed client-cleanup is not completed as it would still left couple temp dirs around and never clean up them if we want a "clean" client/python directory that matches to what we have out of box. Here are the changes:

1. Wording changes around what will be clenaup
2. Cleanup client/python/dist dir (this got created via make client-build
3. Cleanup client/python/spec and client/python/.openapi-generator dirs (these got created via make client-regenerate
4. Cleanup client/python/.pytest_cache dir (this got created via make client-integration-test)
5. Cleanup clien/python/**/__pycache__ dirs (these got created via client-regenerate)
6. Remove cleanup over *.pyc as those are part of __pycache__ since python3 and it will be cleanup along with item 5.
7. Remove unnecessary conditional check on VENV_DIR cleanup to match to the rest of the cleanup.

Checklist

• 🛡️ Don't disclose security issues! (contact security@apache.org)
• 🔗 Clearly explained why the changes are needed, or linked related issues: Fixes #
• 🧪 Added/updated tests with good coverage, or manually tested (and explained how)
• 💡 Added comments for complex logic
• 🧾 Updated CHANGELOG.md (if needed)
• 📚 Updated documentation in site/content/in-dev/unreleased (if needed)