Detect and verify JVM AOT cache recording during integration tests

[vpelikh]

Introduce AotCacheTestExecutionListener, registered by default in the TestContext framework. It activates automatically when the test JVM is started with AOT cache recording enabled via the JDK 25+ single-step -XX:AOTCacheOutput=<path> flag, injected by the Spring Boot Maven or Gradle plugins.

The JVM performs the actual cache generation. This listener coordinates the training run and verifies the outcome:

• Validates the JDK version (JDK 25+, JEP 514).
• Eagerly loads the ApplicationContext so that context creation is captured as part of the training workload.
• Warns when the application class loader is not a standard JDK class loader (AOT cache only caches classes loaded by JDK built-in class loaders).
• Warns when -Dspring.context.exit=onRefresh is set, since it would terminate the test JVM mid-run.
• Verifies on JVM exit that the cache file was produced at the path specified by the -XX:AOTCacheOutput flag.

Why

This PR is part of #36774. Generating the JVM AOT cache from integration tests lets a realistic test suite exercise a broader portion of the application's startup and request-handling workflow than a simple -Dspring.context.exit=onRefresh run, producing a more effective cache. The cache also stores method profiling information, so exercising realistic code paths improves warmup behavior as well.

How it works

• No Spring configuration or property is required: the JVM flags are the single source of truth for whether recording is enabled and where the cache is written. The listener only detects flags via RuntimeMXBean.getInputArguments().
• By convention, the cache is written to aot-cache/application.aot relative to the test working directory, matching the location detected by the Paketo Spring Boot buildpack and bundled into the image by the Spring Boot build plugins.
• The listener is registered by default and is a no-op unless AOT cache recording is enabled, so it does not affect regular test runs.

Documentation

• integration/aot-cache.adoc: new "Generating the cache from integration tests" section.
• testcontext-framework/tel-config.adoc and TestExecutionListener javadoc: added the listener to the default listener list.

Notes

• JDK 24 is not supported. It is not an LTS release and it has a different flow for AOT cache generation (JEP 483), so it's not worth adding support for it now; it can be done as a follow-up if needed.

Related PRs

• Spring Boot PR Add AOT cache recording to build plugins and bootBuildImage spring-boot#51101 adds AOT cache support to the Spring Boot Maven and Gradle plugins: a new aotCacheRecord option that injects the -XX:AOTCacheOutput JVM flag into the test JVM forked by the plugin, so that running tests also records the AOT cache. The PR was closed and needs to be recreated to provide full support for generating the cache from integration tests.
• Paketo buildpack PR Support pre-recorded AOT cache in container images paketo-buildpacks/spring-boot#609 adds support in the buildpacks for a pre-recorded AOT cache.

[vpelikh]

CC @sdeleuze

[vpelikh]

Fixed CI failures in 57d0ee0.