Expand SAML Deprecations What's New

Issue gh-11077

docs/modules/ROOT/pages/whats-new.adoc

@@ -41,6 +41,12 @@ Instead, use `requestMatchers` or `HttpSecurity#securityMatchers`.
 * https://github.com/spring-projects/spring-security/issues/11110[gh-11110] - Require explicit session saves by default
 * https://github.com/spring-projects/spring-security/issues/11057[gh-11057] - Remove `MessageSourceAware` from `ExceptionTranslationWebFilter`
 * https://github.com/spring-projects/spring-security/issues/12022[gh-12202] - Remove OAuth deprecations
+* Remove `Converter` constructors from `Saml2MetadataFilter` and `Saml2AuthenticationTokenConverter`
+* Remove `Saml2AuthenticationRequestContextResolver` and `Saml2AuthenticationRequestFactory`
+* Remove `Saml2AuthenticationToken(String, String, String, String, List)
+* Remove `RelyingPartyRegistration.ProviderDetails`
+* Remove `OpenSamlAuthenticationProvider`
+
 * Remove SAML deprecations
 
 == Core