openssh: update to OpenSSH v8.7p1

Some notable changes, from upstream's release notes:

• sshd(8): Remove support for obsolete "host/port" syntax.
• ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes".
• ssh-keygen(1): when acting as a CA and signing certificates with an RSA key, default to using the rsa-sha2-512 signature algorithm.
• ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures.
• ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one).
• ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions.
• scp(1): this release changes the behaviour of remote to remote copies (e.g. "scp host-a:/path host-b:") to transfer through the local host by default.
• scp(1): experimental support for transfers using the SFTP protocol as a replacement for the venerable SCP/RCP protocol that it has traditionally used.

Additional integration work is needed to support FIDO/U2F in the base
system.

Deprecation Notice

OpenSSH will disable the ssh-rsa signature scheme by default in the
next release.

Reviewed by: imp
MFC after: 1 month
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29985