We updated our RSA SSH host key

On March 24, GitHub replaced its RSA SSH host key for Git operations as a precautionary step after discovering that the private key was inadvertently exposed in a public GitHub repository, though there was no indication of misuse or compromise of customer data. This change affects only RSA SSH Git operations, leaving web traffic and HTTPS operations unaffected, and requires users experiencing host key verification issues to update their known_hosts file accordingly. GitHub emphasized that the exposure was not due to a security breach but rather an accidental publication, and users employing ECDSA or Ed25519 keys remain unaffected. GitHub Actions users might encounter workflow disruptions if using certain configurations, prompting updates to the actions/checkout action. The announcement was made by Mike Hanley, GitHub's Chief Security Officer, who has a background in leading security initiatives at Duo Security and Cisco.