chore(camel-test-infra-kafka): upgrade confluent.container.image to 8.3.1

[github-actions]

This PR updates the confluent.container.image container image to version 8.3.1.

Update Details

• Property: confluent.container.image
• Image: mirror.gcr.io/confluentinc/cp-kafka
• File: /home/runner/work/camel/camel/test-infra/camel-test-infra-kafka/src/main/resources/org/apache/camel/test/infra/kafka/services/container.properties
• Old version: 8.3.0
• New version: 8.3.1

Verification

Please verify:

• Container image version is compatible with existing tests
• No breaking changes in the updated version
• Tests pass with the new version

Run the following to rebuild the test infra:

mvn clean verify -pl camel-test-infra-kafka

Then test the impacted components.

---

This PR was automatically created by the Container Version Upgrade workflow.

[gnodet]

✅ Local IT results for 15a812fb2dd0559cfcf8494173db8d79bce1b1ed

All integration tests passed locally (excluding pre-existing flaky test)

Test-infra module: camel-test-infra-kafka
Components tested: camel-kafka

Component	IT Tests	Passed	Failed	Result
camel-kafka	25	23	2	✅ (failures are pre-existing)

Note on failures: KafkaConsumerUnresolvableHealthCheckIT (2 test methods) fails identically on main — this is a pre-existing flaky test unrelated to the confluent 8.3.1 upgrade. Verified by running the same test against main branch.

Failing test details (pre-existing, not a regression)

KafkaConsumerUnresolvableHealthCheckIT.testReportCorrectlyWhenDown:
  ConditionTimeoutException: readiness check expected: <true> but was: <false> within 20 seconds.

KafkaConsumerUnresolvableHealthCheckIT.kafkaConsumerHealthCheck:
  mock://result Received message count. Expected: <0> but was: <5>

Same failures observed on main branch — confirmed pre-existing flaky test.

Full test output

Integration tests:
  Tests run: 25, Failures: 1, Errors: 1, Skipped: 0
  (23 of 25 tests passed; 2 failures are pre-existing on main)

BUILD completed in 08:37 min

Local integration tests run by ForgeBot on behalf of @gnodet
Tests run without -Dci.env.name to include ITs disabled on GitHub Actions CI