gh-138143: Allow anonymous unions in public headers, using `_Py_ANONY… · python/cpython@ce1a877

`$HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK` is set: not checking for outdated dependents or dependents with broken linkage!

xz 5.8.1 is already installed and up-to-date. To reinstall 5.8.1, run: brew reinstall xz

pkgconf 2.5.1 is already installed and up-to-date. To reinstall 2.5.1, run: brew reinstall pkgconf