chore(deps): bump org.jenkins-ci.plugins:plugin from 4.88 to 5.6

Bumps [org.jenkins-ci.plugins:plugin](https://github.com/jenkinsci/plugin-pom) from 4.88 to 5.6.
- [Release notes](https://github.com/jenkinsci/plugin-pom/releases)
- [Changelog](https://github.com/jenkinsci/plugin-pom/blob/master/CHANGELOG.md)
- [Commits](jenkinsci/plugin-pom@plugin-4.88...plugin-5.6)

---
updated-dependencies:
- dependency-name: org.jenkins-ci.plugins:plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>org.jenkins-ci.plugins</groupId>
         <artifactId>plugin</artifactId>
-        <version>4.88</version>
+        <version>5.6</version>
         <relativePath />
     </parent>