[FLINK-30537] Update Opensearch dependency to version 2.3

[amirhalatzi]

Hi!

During a project we're working on we decided to use Flink over Opensearch 2.3, which seems to have a breaking change of removing the type property from responses.

This PR updates the dependency and the relevant tests.

I'd be happy to do any necessary changes to make sure this release is differentiated from the one meant for Opensearch 1.3.

Thanks!

[boring-cyborg]

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[reta]

@amirhalatzi the OpenSearch 2.x has JDK-11 baseline (the connector works with 2.x as well). Please correct me if I am wrong, Apache Flink still supports JDK 8 (although it is deprecated).

[amirhalatzi]

@reta you're right. Java 8 is still supported. As for the current connector working with 2.x - you can see in the PR that the API has changed.
Any ideas on how to support both versions without upgrading to Java 11?

[reta]

@reta you're right. Java 8 is still supported. As for the current connector working with 2.x - you can see in the PR that the API has changed. Any ideas on how to support both versions without upgrading to Java 11?

@amirhalatzi this is only test code which uses type, sadly the Bulk API in 1.x requires it (at least for responses), it might be possible to rewrite this test case as integration (in this case the responses don't need to be mocked). The connector's code itself does not use any deprecated APIs though.