compatibility-version: update beta criteria.

Signed-off-by: Siyuan Zhang <[email protected]>

Author: siyuanfoundation

keps/sig-architecture/4330-compatibility-versions/README.md

@@ -879,6 +879,8 @@ We intend to have this up and running for Beta
 - Compatibility version support for N-3 minor versions
 - Clients send version number and servers report out-of-allowance skew to a metric
   (Leveraging work from KEP-4355 if possible)
+- All existing features migrated to versioned feature gate - [kubernetes #125031](https://github.com/kubernetes/kubernetes/issues/125031)
+- Verification machinery added - [kubernetes #125032](https://github.com/kubernetes/kubernetes/issues/125032) 
 
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 **Note:** *Not required until targeted at a release.*