README.md: bump Maintenance badge to 2026

Author: jimklimov

README.md

@@ -5,7 +5,7 @@
 [![Jenkins Plugin Installs](https://img.shields.io/jenkins/plugin/i/lockable-resources.svg?color=blue)](https://plugins.jenkins.io/lockable-resources)
 [![Build Status](https://ci.jenkins.io/buildStatus/icon?job=Plugins%2Flockable-resources-plugin%2Fmaster)](https://ci.jenkins.io/job/Plugins/job/lockable-resources-plugin/job/master/)
 [![GitHub license](https://img.shields.io/github/license/jenkinsci/lockable-resources-plugin.svg)](https://github.com/jenkinsci/lockable-resources-plugin/blob/master/LICENSE.txt)
-[![Maintenance](https://img.shields.io/maintenance/yes/2025.svg)](https://github.com/jenkinsci/lockable-resources-plugin)
+[![Maintenance](https://img.shields.io/maintenance/yes/2026.svg)](https://github.com/jenkinsci/lockable-resources-plugin)
 [![Crowdin](https://badges.crowdin.net/e/656dcffac5a09ad0fbdedcb430af1904/localized.svg)](https://jenkins.crowdin.com/lockable-resources-plugin)
 [![Join the chat at https://gitter.im/jenkinsci/lockable-resources](https://badges.gitter.im/jenkinsci/lockable-resources.svg)](https://gitter.im/jenkinsci/lockable-resources?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)