Add oidc-required-claim (#12536)

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

@@ -322,6 +322,7 @@ To enable the plugin, configure the following flags on the API server:
 | `--oidc-username-prefix` | Prefix prepended to username claims to prevent clashes with existing names (such as `system:` users). For example, the value `oidc:` will create usernames like `oidc:jane.doe`. If this flag isn't provided and `--oidc-user-claim` is a value other than `email` the prefix defaults to `( Issuer URL )#` where `( Issuer URL )` is the value of `--oidc-issuer-url`. The value `-` can be used to disable all prefixing. | `oidc:` | No |
 | `--oidc-groups-claim` | JWT claim to use as the user's group. If the claim is present it must be an array of strings. | groups | No |
 | `--oidc-groups-prefix` | Prefix prepended to group claims to prevent clashes with existing names (such as `system:` groups). For example, the value `oidc:` will create group names like `oidc:engineering` and `oidc:infra`. | `oidc:` | No |
+| `--oidc-required-claim` | A key=value pair that describes a required claim in the ID Token. If set, the claim is verified to be present in the ID Token with a matching value. Repeat this flag to specify multiple claims. | `claim=value` | No |
 | `--oidc-ca-file` | The path to the certificate for the CA that signed your identity provider's web certificate.  Defaults to the host's root CAs. | `/etc/kubernetes/ssl/kc-ca.pem` | No |
 
 Importantly, the API server is not an OAuth2 client, rather it can only be