Related to https://gitlab.com/gitlab-org/gitlab/-/issues/213259.

This MR provides support "ecdsa-sk" and "ed25519-sk" SSH keys.

In https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77374,
   https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77403,
   https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77996,
   https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77424,
   and https://gitlab.com/gitlab-org/gitlab/-/merge_requests/78532 we have done
   the work that facilitates support "ecdsa-sk" and "ed25519-sk" SSH keys.

By adding support "ecdsa-sk" and "ed25519-sk" SSH keys, we provide a new,
more secure, and easy-to-use way to strongly authenticate with Git
while preventing unintended and potentially malicious access.
For instance, if a user's private key file on their computer is stolen,
it would be useless without the user's security key.

Demo: Using "ecdsa-sk" and "ed25519-sk" SSH keys - https://www.youtube.com/watch?v=DtmZEVguN7g

Read:
- OpenSSH 8.2 release notes: https://www.openssh.com/releasenotes.html#8.2
- OpenSSH's support for U2F/FIDO security keys:
  https://github.com/openssh/openssh-portable/blob/8a0848cdd3b25c049332cd56034186b7853ae754/PROTOCOL.u2f
- https://cloud.google.com/compute/docs/tutorials/ssh-with-sk
- https://www.yubico.com/blog/github-now-supports-ssh-security-keys/
- https://github.blog/2021-05-10-security-keys-supported-ssh-git-operations/

Changelog: added