Fixed CHANGELOG, the API version should be 1.31.0, the release tooling

mistook 1.31.1 API.

Author: yliaog

CHANGELOG.md

@@ -1,16 +1,11 @@
 # v31.0.0
 
-Kubernetes API Version: v1.31.1
-
-### API Change
-- The resource/v1alpha3.ResourceSliceList filed which should have been named "metadata" but was instead named "listMeta" is now properly "metadata". ([kubernetes/kubernetes#126761](https://github.com/kubernetes/kubernetes/pull/126761), [@thockin](https://github.com/thockin)) [SIG API Machinery]
-
+Kubernetes API Version: v1.31.0
 
 # v31.0.0b1
 
 Kubernetes API Version: v1.31.0
 
-
 # v31.0.0a1
 
 Kubernetes API Version: v1.31.0