Add release notes for changes on update-kubeconfig

Author: yuxiang-zhang

.changes/next-release/bugfix-eks-66737.json

@@ -0,0 +1,5 @@
+{
+  "type": "bugfix",
+  "category": "eks",
+  "description": "Fix eks kubeconfig validations closes `#6564 <https://github.com/aws/aws-cli/issues/6564>`__, fixes `#4843 <https://github.com/aws/aws-cli/issues/4843>`__, fixes `#5532 <https://github.com/aws/aws-cli/issues/5532>`__"
+}