Default spring.aot.repositories.enabled to true when AOT is active

[HyunSangHan]

Resolves: #3899

Currently, to leverage AOT optimized repositories on the JVM with Spring Data JPA, users need to explicitly set both spring.aot.enabled=true and spring.aot.repositories.enabled=true.

This change updates the behavior so that if Spring Framework's AOT processing is active (e.g., spring.aot.enabled=true is set, or the application is being prepared for a native image), Spring Data JPA's AOT repository generation (spring.aot.repositories.enabled) will also be enabled by default.