Add known issues for Javascript

[adarshsanjeev]

Java 17 does not support Javascript as support for the Nashorn JavaScript Engine was dropped. Till #14795 is merged, Javascript tiered broker selector strategy and Javascript filter would not work in Java 17. This PR documents this as a known issue.

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This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• 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.

[kfaraz]

Maybe also mention the corresponding Druid versions where javascript filters wouldn't work since we have dropped support for JDK 8 and 11.