ci update freebsd version proposal, freebsd 12 being eol raising to the lowest still active supported freebsd version. From 13.1 (already eol too), freebsd introduces a cpu affinity layer with linux. It also introduces a api compatible copy_file_range which can be used like its linux's counterpart. The former is essential to build https://github.com/rust-lang/rust/pull/120589, therefore breaks the backward compatibility with the previous FreeBSD releases. Blocked on https://github.com/rust-lang/rust/issues/130465