Move classpath checks to class member variable

[marcusdacoregio]

This commit spring-projects/spring-framework@22a750f which is now merged in Spring Framework main, added a GraalVM feature that makes constant at build-time 2 type of fields:

• NativeDetector#imageCode
• Static fields with a name ending by Present in org.springframework package that are typically used for classpath check with ClassUtils#isPresent

See:

• Replace build-time initialization by constant field evaluation at build-time spring-framework#28624
• https://github.com/spring-projects/spring-framework/wiki/Spring-AOT-and-native-support#build-time-fields-initialization-for-classpath-checks

That said, we should go throughout the codebase and make sure we follow that convention