Upgrade plugin parent POM to latest (#1702)

pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>org.jenkins-ci.plugins</groupId>
     <artifactId>plugin</artifactId>
-    <version>4.88</version>
+    <version>5.1</version>
     <relativePath />
   </parent>
 
@@ -54,17 +54,14 @@
     <changelist>-SNAPSHOT</changelist>
     <jenkins.baseline>2.462</jenkins.baseline>
     <!-- <jenkins.version>${jenkins.baseline}.3</jenkins.version> -->
-    <!-- TODO: Remove when 2.475 is available in LTS -->
-    <jenkins.version>2.475</jenkins.version>
+    <!-- TODO: Remove when 2.479 is available in LTS -->
+    <jenkins.version>2.479</jenkins.version>
     <spotbugs.effort>Max</spotbugs.effort>
     <spotbugs.threshold>Low</spotbugs.threshold>
     <gitHubRepo>jenkinsci/${project.artifactId}</gitHubRepo>
     <hpi.compatibleSinceVersion>1.4.0</hpi.compatibleSinceVersion>
     <mockserver.version>5.15.0</mockserver.version>
     <spotless.check.skip>false</spotless.check.skip>
-    <!-- TODO JENKINS-73339 until in parent POM -->
-    <jenkins-test-harness.version>2265.v3da_49c8134d6</jenkins-test-harness.version>
-    <maven.compiler.release>17</maven.compiler.release>
   </properties>
 
   <dependencyManagement>
@@ -77,12 +74,6 @@
         <type>pom</type>
         <scope>import</scope>
       </dependency>
-      <!-- TODO JENKINS-73339 until in parent POM, work around https://github.com/jenkinsci/plugin-pom/issues/936 -->
-      <dependency>
-        <groupId>jakarta.servlet</groupId>
-        <artifactId>jakarta.servlet-api</artifactId>
-        <version>6.1.0</version>
-      </dependency>
     </dependencies>
   </dependencyManagement>