Upgrade to Thymeleaf and Security Extras 3.1.0-M1

Closes gh-49452
Closes gh-49453

spring-boot-project/spring-boot-cli/samples/ui.groovy

@@ -1,6 +1,6 @@
 package app
 
-@Grab("thymeleaf-spring5")
+@Grab("thymeleaf-spring6")
 @Controller
 class Example {
 
@@ -10,24 +10,3 @@ class Example {
 		return "home"
 	}
 }
-
-@Configuration(proxyBeanMethods = false)
-@Log
-class MvcConfiguration extends WebMvcConfigurerAdapter {
-
-	@Override
-	void addInterceptors(InterceptorRegistry registry) {
-		log.info "Registering interceptor"
-		registry.addInterceptor(interceptor())
-	}
-
-	@Bean
-	HandlerInterceptor interceptor() {
-		log.info "Creating interceptor"
-		[
-			postHandle: { request, response, handler, mav ->
-				log.info "Intercepted: model=" + mav.model
-			}
-		] as HandlerInterceptorAdapter
-	}
-}