Require Jenkins 2.401.3 or newer (#306)

Jenkins 2.426.1 will release Nov 15, 2023.  When it releases, the
recommendation for minimum Jenkins version support will increase
to Jenkins 2.401.3.  Since the plugin bill of materials is no longer
updating the 2.387.x line, this pull request switches to use Jenkins
2.401.x as the new minimum Jenkins version.

This change is not significant enough to require a new release of
the plugin.  It is enough that when the next release happens, it will
require Jenkins 2.401.3 or newer.

pom.xml

@@ -45,7 +45,7 @@
     <revision>5.0.1</revision>
     <changelist>-SNAPSHOT</changelist>
     <gitHubRepo>jenkinsci/priority-sorter-plugin</gitHubRepo>
-    <jenkins.version>2.387.3</jenkins.version>
+    <jenkins.version>2.401.3</jenkins.version>
     <pmdVersion>6.55.0</pmdVersion>
     <spotbugs.effort>Max</spotbugs.effort>
     <spotbugs.threshold>Low</spotbugs.threshold>
@@ -56,8 +56,8 @@
     <dependencies>
       <dependency>
         <groupId>io.jenkins.tools.bom</groupId>
-        <artifactId>bom-2.387.x</artifactId>
-        <version>2543.vfb_1a_5fb_9496d</version>
+        <artifactId>bom-2.401.x</artifactId>
+        <version>2555.v3190a_8a_c60c6</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>