Use jenkins.baseline to reduce bom update mistakes

pom.xml

@@ -10,8 +10,9 @@
     <properties>
         <revision>1</revision>
         <changelist>999999-SNAPSHOT</changelist>
-        <!-- Baseline Jenkins version you use to build the plugin. Users must have this version or newer to run. -->
-        <jenkins.version>2.440.3</jenkins.version>
+        <!-- https://www.jenkins.io/doc/developer/plugin-development/choosing-jenkins-baseline/ -->
+        <jenkins.baseline>2.440</jenkins.baseline>
+        <jenkins.version>${jenkins.baseline}.3</jenkins.version>
         <hpi.compatibleSinceVersion>1.9</hpi.compatibleSinceVersion>
     </properties>
     <artifactId>stashNotifier</artifactId>
@@ -80,7 +81,7 @@
         <dependencies>
             <dependency>
                 <groupId>io.jenkins.tools.bom</groupId>
-                <artifactId>bom-2.440.x</artifactId>
+                <artifactId>bom-${jenkins.baseline}.x</artifactId>
                 <version>3387.v0f2773fa_3200</version>
                 <scope>import</scope>
                 <type>pom</type>