This commit refines how GraalVM tracing agent detection works
for both test and application executions.
It rolls back the introduction of TestAotDetector done in 111309605c
and instead updates AotDetector.useGeneratedArtifacts()
to only detect "buildtime" and "runtime" imagecode system
property values by leveraging a new method
NativeDetector.inNativeImage(NativeDetector.Context...).
This commit also adds a workaround for
https://github.com/oracle/graal/issues/6691.
Closes gh-30511
1cf6d1dd9d