ssh: update to OpenSSH v8.9p1

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

(cherry picked from commit 1323ec571215a77ddd21294f0871979d5ad6b992)
(cherry picked from commit 58def461e256e3a05c3ff15a87ed702fe0c3662c)