Use jenkins.baseline to reduce bom update mistakes (#1283)

Author: strangelookingnerd

pom.xml

@@ -63,8 +63,10 @@
   <properties>
     <revision>1.12.772</revision>
     <changelist>999999-SNAPSHOT</changelist>
-    <bom>2.440.x</bom>
-    <jenkins.version>2.440.3</jenkins.version>
+    <bom>${jenkins.baseline}.x</bom>
+    <!-- https://www.jenkins.io/doc/developer/plugin-development/choosing-jenkins-baseline/ -->
+    <jenkins.baseline>2.440</jenkins.baseline>
+    <jenkins.version>${jenkins.baseline}.3</jenkins.version>
     <autoVersionSubmodules>true</autoVersionSubmodules>
     <spotless.check.skip>false</spotless.check.skip>
   </properties>