[7.7] Document new xpack.security.authc.* settings and related 8.0.0 breaking changes. (#62179)

Author: azasypkin

docs/setup/settings.asciidoc

@@ -415,9 +415,7 @@ all http requests to https over the port configured as `server.port`.
 supported protocols with versions. Valid protocols: `TLSv1`, `TLSv1.1`, `TLSv1.2`
 
 `server.xsrf.whitelist:`:: It is not recommended to disable protections for
-arbitrary API endpoints. Instead, supply the `kbn-xsrf` header. There are some
-scenarios where whitelisting is required, however, such as
-<<kibana-authentication, SAML and OpenID Connect Single Sign-On setups>>.
+arbitrary API endpoints. Instead, supply the `kbn-xsrf` header.
 The `server.xsrf.whitelist` setting requires the following format:
 
 [source,text]