Replace outdated Spring Integration metrics section with a link

spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc

@@ -1601,6 +1601,7 @@ Spring Boot registers the following core metrics when applicable:
 * Uptime metrics: report a gauge for uptime and a fixed gauge representing the
 application's absolute start time
 * Tomcat metrics
+* https://docs.spring.io/spring-integration/docs/current/reference/html/system-management-chapter.html#micrometer-integration[Spring Integration] metrics
 
 
 
@@ -1704,14 +1705,6 @@ To customize the tags, provide a `@Bean` that implements
 
 
 
-[[production-ready-metrics-integration]]
-==== Spring Integration metrics
-When Spring Integration is available, a `timer` and `errorCounter` are registered for each
-`MessageHandler` and `MessageChannel`. For each `MessageSource`, a `counter` is
-registered.
-
-
-
 [[production-ready-metrics-cache]]
 ==== Cache Metrics
 Auto-configuration enables the instrumentation of all available ``Cache``s on startup