Update documentation for Buildpack's AOT Cache support

Starting with the [Spring Boot buildpack](https://github.com/paketo-buildpacks/spring-boot) version 5.35.0, AOT cache can be enabled by setting the env variable `BP_JVM_AOTCACHE_ENABLED` to `true`. That works with Java 25+. If Java < 25 is used, a fallback to CDS is automatically performed.