Fix broken links to upgrade notes

Spring-Framework-6.1-Release-Notes.md

@@ -208,7 +208,7 @@ By default, if an error is encountered during build-time AOT processing, an exce
 
 ### Web Applications
 
-* Spring MVC and WebFlux now have built-in method validation support for controller method parameters with `@Constraint` annotations. That means you no longer need `@Validated` at the controller class level to enable method validation via an AOP proxy. Built-in method validation is layered on top of the existing argument validation for model attribute and request body arguments. The two are more tightly integrated and coordinated, e.g. avoiding cases with double validation. See [Upgrading to 6.1](https://github.com/spring-projects/spring-framework/wiki/Upgrading-to-Spring-Framework-6.x#web-applications) for migration details and umbrella issue [30645](https://github.com/spring-projects/spring-framework/issues/30645) for all related tasks and feedback.
+* Spring MVC and WebFlux now have built-in method validation support for controller method parameters with `@Constraint` annotations. That means you no longer need `@Validated` at the controller class level to enable method validation via an AOP proxy. Built-in method validation is layered on top of the existing argument validation for model attribute and request body arguments. The two are more tightly integrated and coordinated, e.g. avoiding cases with double validation. See the [upgrade notes](#web-applications) for migration details and umbrella issue [30645](https://github.com/spring-projects/spring-framework/issues/30645) for all related tasks and feedback.
 * Method validation is supported with method parameters that are collections, arrays, or maps of objects.
 * The `HandlerMethodValidationException` raised by the new built-in method validation exposes a `Visitor` API to process validation errors by controller method parameter type, e.g. `@RequestParameter`, `@PathVariable`, etc. 
 * `MethodValidationInterceptor` supports validation of `Mono` and `Flux` method parameters; see issue [20781](https://github.com/spring-projects/spring-framework/issues/20781).
@@ -238,7 +238,7 @@ Spring MVC and WebFlux now support data binding via constructors, including nest
 * STOMP messaging supports a new `preserveReceiveOrder` config option for ordered processing of messages received from a given client. That's in addition to the existing `preservePublishOrder` flag for messages published to clients; see the [Order of Messages](https://docs.spring.io/spring-framework/reference/6.1/web/websocket/stomp/ordered-messages.html) section of the reference docs.
 * The `@RSocketExchange` annotation used on RSocket interface methods is now supported for responder-side handling as an alternative to `@MessageMapping`; see [@RSocketExchange](https://docs.spring.io/spring-framework/reference/6.1-SNAPSHOT/rsocket.html#rsocket-annot-rsocketexchange) for more details and guidance.
 * Interface parameter annotations are detected for messaging handler methods as well (analogous to web handler methods).
-* The SpEL-based `selector` header support in WebSocket messaging is now disabled by default and must be explicitly enabled; see [30550](https://github.com/spring-projects/spring-framework/issues/30550) and [Upgrading to 6.1](https://github.com/spring-projects/spring-framework/wiki/Upgrading-to-Spring-Framework-6.x#messaging-applications) for migration details.
+* The SpEL-based `selector` header support in WebSocket messaging is now disabled by default and must be explicitly enabled; see [30550](https://github.com/spring-projects/spring-framework/issues/30550) and the [upgrade notes](#messaging-applications) for migration details.
 * Observability support for JMS: Spring Framework now produces observations when publishing messages with `JmsTemplate` and when processing messages with `MessageListener` or `@JmsListener`; see [the reference docs section](ttps://docs.spring.io/spring-framework/reference/6.1/integration/observability.html#observability.jms) and issue [30335](https://github.com/spring-projects/spring-framework/issues/30335).
 
 ### Testing
@@ -260,6 +260,6 @@ Spring MVC and WebFlux now support data binding via constructors, including nest
 * `MockMvcWebTestClient` now supports the `RequestPostProcessor` hook which can, for example, allow varying user identity across tests; see [31298](https://github.com/spring-projects/spring-framework/issues/31298).
 * `MockRestServiceServer` supports the new `RestClient` in addition to the `RestTemplate`.
 * Support for `null` in `MockHttpServletResponse.setCharacterEncoding()`; see [30341](https://github.com/spring-projects/spring-framework/issues/30341).
-* Errors encountered during build-time AOT processing now cause the build to fail immediately. This behavior can be disabled by setting the `spring.test.aot.processing.failOnError` property to `false`. See [Upgrading to 6.1](https://github.com/spring-projects/spring-framework/wiki/Upgrading-to-Spring-Framework-6.x#messaging-applications) for migration details.
+* Errors encountered during build-time AOT processing now cause the build to fail immediately. This behavior can be disabled by setting the `spring.test.aot.processing.failOnError` property to `false`. See the [upgrade notes](#testing) for migration details.
 * New `@⁠DisabledInAotMode` annotation that can be used to disable AOT build-time processing of a test's `ApplicationContext` and to disable an entire test class or a single test method at run time when the test suite is run with AOT optimizations enabled.
-* `@Resource` may now be used for dependency injection in test classes when running in AOT mode.
+* `@Resource` may now be used for dependency injection in test classes when running in AOT mode.