0.8.0

What's Changed

• Drop Python 2 support and all compatibility code (IS_PYTHON_2, _unicodify, six, unittest2)
• Supported Python versions: 3.10–3.14
• Replace flake8 with ruff
• Add Dependabot for automated dependency updates
• Modernize CI: bump GitHub Actions to v4/v5, use pip install instead of setup.py
• Remove stale .travis.yml, tox.ini, and EOL Python Docker images
• Add branch protection requiring CI to pass before merge