chore: add support for Python 3.14

[jtroup]

what

Added support for Python 3.14 to the Stacklet MCP server. This includes:

• Updated CI pipeline to run tests on Python 3.12, 3.13, and 3.14 using a matrix strategy
• Added Python 3.14 classifier to pyproject.toml
• Updated development tooling:
  • uv from 0.8.14 to 0.9.5
  • pre-commit repos (ruff-pre-commit, pyproject-fmt & mypy)
• Updated all Python dependencies
• Bumped package version from 0.1.1 to 2025.11.0
• Created NEWS.md to document the Python 3.14 support

why

To ensure the Stacklet MCP server is compatible with the latest Python release (3.14) and to keep development tooling up to date. This allows users to run the server on Python 3.14 and ensures the codebase continues to work with modern Python features and improvements.

testing

The GitHub Actions CI workflow now includes a test matrix that runs the full pytest test suite on Python versions 3.12, 3.13, and 3.14. The uv run --python ${{ matrix.python-version }} pytest --cov command ensures tests pass on all supported Python versions.

docs

• A NEWS.md file was added documenting the Python 3.14 support feature.
• The pyproject.toml classifiers now accurately reflect the supported Python versions (3.12, 3.13, and 3.14).