Update 3.6 changelog to cover the endpoint status not returning wrong quota

Signed-off-by: Benjamin Wang <[email protected]>

Author: ahrtr

CHANGELOG/CHANGELOG-3.6.md

@@ -10,6 +10,7 @@ Previous change logs can be found at [CHANGELOG-3.5](https://github.com/etcd-io/
 
 - [Reject watch request with -1 revision to prevent invalid resync behavior on uncompacted etcd](https://github.com/etcd-io/etcd/pull/20707)
 - [Change the TLS handshake 'EOF' errors to DEBUG not to spam logs](https://github.com/etcd-io/etcd/pull/20749)
+- Fix [endpoint status not retuning the correct storage quota](https://github.com/etcd-io/etcd/pull/20790)
 
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