Rename FreeBSD* pkg repos to FreeBSD-ports*

With pkgbase being the New Way Of Doing Things in FreeBSD 15.0, it is
unnecessarily confusing to have a repository called "FreeBSD" which
contains packages built from the FreeBSD ports tree but not from the
FreeBSD src tree. Bite the bullet and change it now rather than
having an even more painful transition later.

With hat: re@
Bikeshed on: freebsd-current, freebsd-ports
Relnotes: The "FreeBSD" and "FreeBSD-kmods" repositories defined

		in /etc/pkg/FreeBSD.conf have been renamed to
		FreeBSD-ports and FreeBSD-ports-kmods respectively.
		Users who override these in /usr/local/etc/pkg/repos
		will need to adjust their configuration to match the
		new names.