Use jenkins.baseline to reduce bom update mistakes

pom.xml

@@ -48,7 +48,8 @@
         <changelist>999999-SNAPSHOT</changelist>
 
         <!-- https://www.jenkins.io/doc/developer/plugin-development/choosing-jenkins-baseline/ -->
-        <jenkins.version>2.361.4</jenkins.version>
+        <jenkins.baseline>2.361</jenkins.baseline>
+        <jenkins.version>${jenkins.baseline}.4</jenkins.version>
         <replacer.version>1.5.3</replacer.version>
 
         <generatedSourcesDir>${project.build.directory}/generated-sources</generatedSourcesDir>
@@ -127,7 +128,7 @@
             <dependency>
                 <!-- Pick up common dependencies for the selected LTS line: https://github.com/jenkinsci/bom#usage -->
                 <groupId>io.jenkins.tools.bom</groupId>
-                <artifactId>bom-2.361.x</artifactId>
+                <artifactId>bom-${jenkins.baseline}.x</artifactId>
                 <version>2102.v854b_fec19c92</version>
                 <type>pom</type>
                 <scope>import</scope>