Enable FreeBSD 12/13 builds on Cirrus CI.
Enable FreeBSD 12/13 builds on Cirrus CI.

The builds were disabled in bb11539a and 164548f2 due to an error that seems to have been caused by a bad package dependency for rsync. In any case adding this fixed it:

pkg update && pkg upgrade -y libiconv

pgbackrest/pgbackrest,pgbackrest/pgbackrest,pgbackrest/pgbackrest