Upgrade to Jandex 3.1.8

[Ladicek]

• https://smallrye.io/blog/jandex-3-1-8/

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit df1b1da.

✅ 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

⚙️ JVM Tests - JDK 21

📦 extensions/smallrye-reactive-messaging-kafka/deployment

✖ io.quarkus.smallrye.reactivemessaging.kafka.deployment.dev.KafkaDevServicesDevModeTestCase.sseStream - History

• Assertion condition defined as a Lambda expression in io.quarkus.smallrye.reactivemessaging.kafka.deployment.dev.KafkaDevServicesDevModeTestCase Expecting size of: [] to be greater than or equal to 2 but was 0 within 10 seconds. - org.awaitility.core.ConditionTimeoutException

org.awaitility.core.ConditionTimeoutException: 
Assertion condition defined as a Lambda expression in io.quarkus.smallrye.reactivemessaging.kafka.deployment.dev.KafkaDevServicesDevModeTestCase 
Expecting size of:
  []
to be greater than or equal to 2 but was 0 within 10 seconds.
	at org.awaitility.core.ConditionAwaiter.await(ConditionAwaiter.java:167)
	at org.awaitility.core.AssertionCondition.await(AssertionCondition.java:119)
	at org.awaitility.core.AssertionCondition.await(AssertionCondition.java:31)

[gastaldi]

Shall this PR be backported?

[Ladicek]

I don't think a backport is necessary.