Python 3.13.1, 3.12.8, 3.11.11, 3.10.16 and 3.9.21 are now available

Another big release day! Python 3.13.1 and 3.12.8 were regularly scheduled releases, but they do contain a few security fixes. That makes it a nice time to release the security-fix-only versions too, so everything is as secure as we can make it.