Add explicit note on JSpecify support in Spring Framework 6.2 vs 7.0

Closes gh-34551

Author: jhoeller

framework-docs/modules/ROOT/pages/core/beans/annotation-config/autowired.adoc

@@ -444,9 +444,9 @@ through Java 8's `java.util.Optional`, as the following example shows:
 	}
 ----
 
-You can also use a `@Nullable` annotation (of any kind in any package -- for example,
-`javax.annotation.Nullable` from JSR-305) or just leverage Kotlin built-in null-safety
-support:
+You can also use a parameter-level `@Nullable` annotation (of any kind in any package --
+for example, `javax.annotation.Nullable` from JSR-305) or just leverage Kotlin built-in
+null-safety support:
 
 [tabs]
 ======
@@ -477,6 +477,13 @@ Kotlin::
 ----
 ======
 
+[NOTE]
+====
+A type-level `@Nullable` annotation such as from JSpecify is not supported in Spring
+Framework 6.2 yet. You need to upgrade to Spring Framework 7.0 where the framework
+detects type-level annotations and consistently declares JSpecify in its own codebase.
+====
+
 You can also use `@Autowired` for interfaces that are well-known resolvable
 dependencies: `BeanFactory`, `ApplicationContext`, `Environment`, `ResourceLoader`,
 `ApplicationEventPublisher`, and `MessageSource`. These interfaces and their extended