gh-actions/test-on-iotlab: bump ssh-agent to v0.4.1
gh-actions/test-on-iotlab: bump ssh-agent to v0.4.1

OlegHahm/RIOT,authmillenon/RIOT,jasonatran/RIOT,kaspar030/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,jasonatran/RIOT,ant9000/RIOT,kaspar030/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,authmillenon/RIOT,authmillenon/RIOT,OlegHahm/RIOT,miri64/RIOT,kYc0o/RIOT,ant9000/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,authmillenon/RIOT,jasonatran/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,ant9000/RIOT,ant9000/RIOT,ant9000/RIOT,miri64/RIOT,OTAkeys/RIOT,kYc0o/RIOT,kYc0o/RIOT,kaspar030/RIOT,miri64/RIOT,jasonatran/RIOT,kaspar030/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,miri64/RIOT,miri64/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,kYc0o/RIOT