Improve configuration API for 1.23

The previous commit for configuration APIs has some nits to fix:

- The client-authentication API has both v1beta1 and v1 supported.
  We need to include both.
- The kube-scheduler v1alpha1 is superceded by v1alpha3 which is new.
- The links to some external type definitions should point to the 1.23
  API rather than old versions.

content/en/docs/reference/access-authn-authz/authentication.md

@@ -1232,3 +1232,5 @@ The following `ExecCredential` manifest describes a cluster information sample.
 ## {{% heading "whatsnext" %}}
 
 * Read the [client authentication reference (v1beta1)](/docs/reference/config-api/client-authentication.v1beta1/)
+* Read the [client authentication reference (v1)](/docs/reference/config-api/client-authentication.v1/)
+