Minor refactor: Move TestBuildChainFunction to its own class

[holly-cummins]

This is a minor refactoring to support https://github.com/orgs/quarkusio/projects/30. It will make the diff smaller on WG 30, but it’s also (ever-so-slightly) valuable in its own right.

This change moves a static inner class out to be its own class. At the moment, we have a superclass referencing an inner class of a descendant class, which is ugly. The descendant class is 1300 lines long, so making it a bit smaller is a bonus. :)

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit 450fd34.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

You can consult the Develocity build scans.

---

Flaky tests - Develocity

⚙️ Native Tests - Security2

📦 integration-tests/oidc-code-flow

✖ io.quarkus.it.keycloak.CodeFlowInGraalITCase.testTokenRefresh - History

• expected: <true> but was: <false> - org.opentest4j.AssertionFailedError

org.opentest4j.AssertionFailedError: expected: <true> but was: <false>
	at io.quarkus.it.keycloak.CodeFlowTest$3.call(CodeFlowTest.java:733)
	at io.quarkus.it.keycloak.CodeFlowTest$3.call(CodeFlowTest.java:720)
	at org.awaitility.core.CallableCondition$ConditionEvaluationWrapper.eval(CallableCondition.java:99)
	at org.awaitility.core.ConditionAwaiter$ConditionPoller.call(ConditionAwaiter.java:248)
	at org.awaitility.core.ConditionAwaiter$ConditionPoller.call(ConditionAwaiter.java:235)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)

[holly-cummins]

Thanks for the review, @geoand! I was going to ask you but you beat me to it :)

[geoand]

:)