It is a follow-up to
JENKINS-48766. https://github.com/jenkinsci/jenkins/commit/dbc75125c565905a9c07b0c83d6ae71b2681c67f in Jenkins 2.104+ exposes the "Remoting-Minimum-Version" header.
It would be great if Remoting verifies this header during the connection and refuses to connect if the version is not supported. If the header is missing, the connection should proceed without a warning.