Fix cron job ITs by using jdk17 as the runtime_jdk

[Akshat-Jain]

Description

Since #17466, the cron job ITs have been broken because they use runtime_jdk: 21.0.4: https://github.com/apache/druid/actions/runs/12078401498/job/33683001077.

Error:

$DRUID_INTEGRATION_TEST_JVM_RUNTIME is set with value 21.0.4
Invalid JVM Runtime given. Stopping

This is because docker_build_containers.sh is checking for Java version 21, but we are using 21.0.4, and hence it errors out.

Adding 21.0.4 in the if-condition won't help, since there's no openjdk:21.0.4-slim-buster image.

This PR changes runtime_jdk to 17 to fix the cron job ITs for now. We can revisit this later on exploring other possible options for which docker image to use for 21.0.4.

---

This PR has:

• been self-reviewed.
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[abhishekrb19]

thanks!