FreshPorts has a need to know the supported both the stable & release branches on #FreeBSD

I don’t want to parse https://www.freebsd.org/security/#sup (for example, I predict errors, often). However, that does seem to be the source of truth.

Perhaps there ports tree has something…

FreshPorts already gets the list of supported ABI from https://pkg.freebsd.org/index.html (details on that at #505 (comment))

I'm hoping for an equally reliable solution. Perhaps I should use freebsd.org/security/#sup after all.