java2x: migrate killbill-plugin-api to jakarta baseline#37

xsalefter merged 2 commits intojava2xkillbill/killbill-plugin-api:java2xfrom

copilot/migrate-killbill-plugin-api-jdk-21killbill/killbill-plugin-api:copilot/migrate-killbill-plugin-api-jdk-21Copy head branch name to clipboard