Add an openzfs-2.3 compatibility file for the next release.
While there are no compatibility difference between Linux and
FreeBSD for 2.3 symlinks for the -linux and -freebsd names are
created for any scripts expecting that convention.
Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#16588
