ssh: update to OpenSSH v8.9p1

Release notes are available at https://www.openssh.com/txt/release-8.9

Some highlights:

* ssh(1), sshd(8), ssh-add(1), ssh-agent(1): add a system for
restricting forwarding and use of keys added to ssh-agent(1)

* ssh(1), sshd(8): add the sntrup761x25519-sha512@openssh.com hybrid
ECDH/x25519 + Streamlined NTRU Prime post-quantum KEX to the
default KEXAlgorithms list (after the ECDH methods but before the
prime-group DH ones). The next release of OpenSSH is likely to
make this key exchange the default method.

* sshd(8), portable OpenSSH only: this release removes in-built
support for MD5-hashed passwords. If you require these on your
system then we recommend linking against libxcrypt or similar.

Future deprecation notice
=========================

A near-future release of OpenSSH will switch scp(1) from using the
legacy scp/rcp protocol to using SFTP by default.

Legacy scp/rcp performs wildcard expansion of remote filenames (e.g.
"scp host:* .") through the remote shell. This has the side effect of
requiring double quoting of shell meta-characters in file names
included on scp(1) command-lines, otherwise they could be interpreted
as shell commands on the remote side.

MFC after: 1 month
Relnotes: Yes
Sponsored by: The FreeBSD Foundation

Properly flatten openssh/dist.

Vendor import of OpenSSH 4.3p1.

Vendor import of OpenSSH 3.8p1.

Vendor import of OpenSSH 3.7.1p2.

Vendor import of OpenSSH-portable 3.5p1.

Vendor import of OpenSSH 3.3p1.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Vendor import of OpenSSH 4.3p1.

Vendor import of OpenSSH 3.8p1.

Vendor import of OpenSSH 3.7.1p2.

Vendor import of OpenSSH-portable 3.5p1.

Vendor import of OpenSSH 3.3p1.