Race-free process creation in the GNU C Library

Very much looking forward to have this available, the combination of race-free pidfd plus race-free spawn in the target cgroup is sorely needed. With this, and the recent SCM_PIDFD/SO_PEERPIDFD addition to kernel v6.5, we are moving towards using pid fds end-to-end across systemd, dbus (-broker/-daemon) and polkit, and any of their clients.