Update maintenance shield year in README.md

Author: Potherca

README.md

@@ -165,7 +165,7 @@ All code created by PDS Interop is licensed under the [MIT License][license-link
 [contributors-page]:  https://github.com/pdsinterop/php-solid-pubsub-server/contributors
 [license-link]: ./LICENSE
 [license-shield]: https://img.shields.io/github/license/pdsinterop/php-solid-pubsub-server.svg
-[maintained-shield]: https://img.shields.io/maintenance/yes/2025
+[maintained-shield]: https://img.shields.io/maintenance/yes/2026
 [pdsinterop-shield]: https://img.shields.io/badge/-PDS%20Interop-gray.svg?logo=data%3Aimage%2Fsvg%2Bxml%3Bbase64%2CPHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9Ii01IC01IDExMCAxMTAiIGZpbGw9IiNGRkYiIHN0cm9rZS13aWR0aD0iMCI+CiAgICA8cGF0aCBkPSJNLTEgNTJoMTdhMzcuNSAzNC41IDAgMDAyNS41IDMxLjE1di0xMy43NWEyMC43NSAyMSAwIDAxOC41LTQwLjI1IDIwLjc1IDIxIDAgMDE4LjUgNDAuMjV2MTMuNzVhMzcgMzQuNSAwIDAwMjUuNS0zMS4xNWgxN2EyMiAyMS4xNSAwIDAxLTEwMiAweiIvPgogICAgPHBhdGggZD0iTSAxMDEgNDhhMi43NyAyLjY3IDAgMDAtMTAyIDBoIDE3YTIuOTcgMi44IDAgMDE2OCAweiIvPgo8L3N2Zz4K
 [pdsinterop-site]: https://pdsinterop.org/
 [project-stage-badge: Development]: https://img.shields.io/badge/Project%20Stage-Development-yellowgreen.svg