Mirroring page: ID icon used for SSH key

The following discussion from !71140 (merged) should be addressed:

• @aqualls started a discussion: (+1 comment)

  For the engineering review: what icon is shown here with Copy SSH public key? I don't have an easy way to verify. The screenshot showing this feature was quite old, and the icon didn't match any of our current icons.

  Tell the TW team which icon it is from this list (https://gitlab-org.gitlab.io/gitlab-svgs/) and we can add the icon inline. It's a more sustainable option than a screenshot.