Deprecate convention-based annotation attribute overrides in favor of `@AliasFor`

[sbrannen]

Overview

Implicit convention-based annotation attribute overrides have been supported for a long time; however, Spring Framework 4.2 introduced support for explicit annotation attribute overrides via @AliasFor.

Since explicit overrides are favorable to implicit overrides, and since the support for convention-based overrides increases the complexity of Spring's annotation search algorithms, we will deprecate convention-based overrides in 6.0 and remove the support in 7.0 (see #28761).

Deliverables

• in 6.0, whenever a convention-based override is detected, log a warning stating the reasons mentioned above