Update jenkins.baseline as requested

Author: daniel-beck

pom.xml

@@ -34,7 +34,7 @@
     <gitHubRepo>jenkinsci/${project.artifactId}-plugin</gitHubRepo>
     <hpi.compatibleSinceVersion>2.2.0</hpi.compatibleSinceVersion>
     <!-- https://www.jenkins.io/doc/developer/plugin-development/choosing-jenkins-baseline/ -->
-    <jenkins.baseline>2.504</jenkins.baseline>
+    <jenkins.baseline>2.528</jenkins.baseline>
     <jenkins.version>2.539</jenkins.version>
     <spotless.check.skip>false</spotless.check.skip>
   </properties>