update CHANGES.md

Author: Beilinson

CHANGES.md

@@ -1,5 +1,17 @@
 # Change Log
 
+## 1.135
+
+### @cesium/engine
+
+#### Breaking Changes :mega:
+
+#### Additions :tada:
+
+#### Fixes :wrench:
+
+- Fix issues with label background when updating properties while `label.show` is `false`. [#12138](https://github.com/CesiumGS/cesium/issues/12138)
+
 ## 1.134 - 2025-10-01
 
 - [Sandcastle](https://sandcastle.cesium.com/) has been updated at `https://sandcastle.cesium.com`! The [legacy Sandcastle app](https://cesium.com/downloads/cesiumjs/releases/1.134/Apps/Sandcastle/index.html) will remain available through November 3, 2025.