[Copilot]

Modernizes the build and CI stack, mirroring the refresh done in pybpf_asm#9.

Build system

• Migrate from scikit-build + setup.py to scikit-build-core with full pyproject.toml metadata
• Flatten CMake layout: merge cyminhook/CMakeLists.txt into root CMakeLists.txt; add LANGUAGES C, use cython_transpile + python_add_library from cython-cmake

CI / GitHub Actions

• Add build-and-test.yml: matrix build across Python 3.9–3.14 on Windows
• Upgrade all actions to v7/v8 (checkout, setup-python, upload-artifact, download-artifact)
• Bump cibuildwheel v2 → v4; drop CIBW_BEFORE_BUILD scikit-build workarounds; runner windows-2019 → windows-2022
• Replace peaceiris/actions-gh-pages with the native actions/configure-pages + upload-pages-artifact + deploy-pages pattern
• Add PyPI trusted publishing (OIDC) replacing token-based publish; split release job with id-token: write permission

Python support

• Drop 3.6–3.8; add 3.14; update classifiers accordingly