1814.vdc9dd5217ee2

👷 Changes for plugin developers

• Bump jetty.version from 10.0.15 to 10.0.16 (#489) @dependabot

👻 Maintenance

• Simplify test matrix (#486) @MarkEWaite
• Test on Java 21 (#485) @MarkEWaite

📦 Dependency updates

• Bump jenkins from 1.102 to 1.105 (#479, #484, #488) @dependabot
• Bump jenkins-test-harness-htmlunit (#481, #487) @dependabot
• Bump jelly.version from 1.1-jenkins-20230124 to 1.1-jenkins-20230713 (#480) @dependabot
• Bump jellydoc-maven-plugin.version (#477, #478) @dependabot