* Add FAQ section on caching cibuildwheel's downloaded tools
Adds a Tips entry covering:
- What cibuildwheel caches (CPython/PyPy installers, virtualenv,
python-build-standalone archives) and the default per-OS cache folder.
- How to override the cache location with ``CIBW_CACHE_PATH``.
- A worked GitHub Actions example pairing ``actions/cache`` with
``CIBW_CACHE_PATH`` so the cache survives between runs.
- A pointer to ``--clean-cache`` for invalidating stale entries.
Closes#1585.
Per @joerick's request in the issue ("a caching section in the FAQ
would be great, if you can contribute it") the scope is intentionally
narrow — just FAQ-level guidance. Platform-specific caching (e.g.
Windows NuGet, addressed in #2839) lives in the platforms doc.
* docs: bump actions/cache v4 to v5
* docs: move cache to runner.temp, add cache poisoning warning (review feedback)
Mike Evdokimov
f4afd95cbc