Add changelog for release v2.26.0-ck8s4

Author: Ajarmar

changelog/2.26.0.md

@@ -67,3 +67,17 @@ Released 2025-02-06
 
 - [e981da2](https://github.com/elastisys/kubespray/commit/e981da2b6595d4e7e73ef4d9e493f3c968df93a8) - reverted changes of commit e99226a
 - [a9a5ee3](https://github.com/elastisys/kubespray/commit/a9a5ee3c33b30d0356ca5b17e3df4dfae3227de7) - fix issue with floating-ip
+
+## v2.26.0-ck8s4
+
+Released 2025-03-04
+
+## Changes by kind
+
+### Feature(s)
+
+- [#421](https://github.com/elastisys/compliantkubernetes-kubespray/pull/421) - update submodule for upcloud ubuntu 24.04 support [@Ajarmar](https://github.com/Ajarmar)
+
+### Other(s)
+
+- [#420](https://github.com/elastisys/compliantkubernetes-kubespray/pull/420) - documentation: Update Ubuntu 24.04 migration guide to include instructions for UpCloud [@Ajarmar](https://github.com/Ajarmar)