Fix Antora warnings

Author: rwinch

docs/modules/ROOT/pages/reactive/oauth2/oauth2-client.adoc

@@ -866,6 +866,7 @@ class OAuth2ClientSecurityConfig : WebSecurityConfigurerAdapter() {
         return http.build()
     }
 }
+----
 ====
 
 ==== Requesting an Access Token
@@ -953,6 +954,7 @@ class OAuth2ClientSecurityConfig {
         return OAuth2AuthorizationCodeReactiveAuthenticationManager(accessTokenResponseClient)
     }
 }
+----
 ====
 
 
@@ -1029,6 +1031,7 @@ val authorizedClientProvider: ReactiveOAuth2AuthorizedClientProvider = ReactiveO
 ...
 
 authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider)
+----
 ====
 
 [NOTE]

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

@@ -7,7 +7,7 @@ Below are the highlights of the release.
 * All new https://antora.org/[Antora] based https://docs.spring.io/spring-security/[documentation].
 
 [[whats-new-servlet]]
-=== Servlet
+== Servlet
 * Core
 
 ** Introduced https://github.com/spring-projects/spring-security/issues/10226[`SecurityContextChangedListener`]
@@ -41,7 +41,7 @@ Below are the highlights of the release.
 ** Added support to https://github.com/spring-projects/spring-security/pull/9737[propagate the TestSecurityContextHolder to SecurityContextHolder]
 
 [[whats-new-webflux]]
-=== WebFlux
+== WebFlux
 
 * OAuth 2.0 Client