Make error message thrown when Quarkus REST and RESTEasy Classic are combined user-friendly again

[michalvavrik]

fixes: #40410

Due to the RESTEasy Reactive to Quarkus REST renaming, the test added in this PR is not backportable.

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit 9e7462c.

✅ 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.

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Flaky tests - Develocity

⚙️ JVM Tests - JDK 17

📦 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)

[gsmet]

LGTM, thanks!