Drop Python versions below 3.11 and add 3.14.0

[Copilot]

This PR updates the Python version support in the reusable GitHub Actions workflows to drop support for Python versions below 3.11 and add support for Python 3.14.0.

Changes

CI Workflow (.github/workflows/ci.yml)

• Updated PYTHON_VERSION_DEFAULT from 3.9.15 to 3.11.14
• Updated PYTHON_MATRIX to remove Python 3.9.15 and 3.10.8, and add Python 3.14.0
• Bumped Python versions to latest patch releases: 3.11.14, 3.12.12, 3.13.8
• New test matrix: "3.11.14", "3.12.12", "3.13.8", "3.14.0"

PyPI Publishing Workflow (.github/workflows/publish-to-pypi.yml)

• Updated PYTHON_VERSION_DEFAULT from "3.9" to "3.11"

Impact

Repositories using these reusable workflows will now:

• Use Python 3.11.14 as the default version for pre-commit, linting, and publishing
• Test against Python 3.11.14, 3.12.12, 3.13.8, and 3.14.0
• No longer test against Python 3.9 or 3.10

This aligns with Python's support lifecycle and allows projects to take advantage of newer Python features while reducing the testing matrix.

Original prompt

Drop Python versions below 3.11 and add 3.14.0.

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