YAHOO.widget.Button

https://github.com/jenkinsci/oracle-cloud-infrastructure-compute-plugin/blob/b2c16b4e7cd23aa98c1cb3ff244aef6afe2e7c92/src/main/resources/com/oracle/cloud/baremetal/jenkins/BaremetalCloud/computerSet.jelly#L23

yui-button

https://github.com/jenkinsci/oracle-cloud-infrastructure-compute-plugin/blob/b2c16b4e7cd23aa98c1cb3ff244aef6afe2e7c92/src/main/resources/com/oracle/cloud/baremetal/jenkins/lib/validateButton.jelly#L11

Replace with '<button class="jenkins-button"... >' (Would require at least 2.375), this is not strictly necessary, Jenkins core can convert such buttons automatically in the future)